•it 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

OIFST   OF" 

Mrs.  SARAH  P.  WALS WORTH. 

Received  October,  1894. 
^Accessions  No .  $%  \  /  ^ .      Class  No , 


NEW   AND   IMPORTANT   WORKS.  7 

From  Prof.  Burnham,  a  Teacher  of  experience,  Principal  of  the  English  Depart- 
ment in  the  well-known  Burr  Seminary ,  and  also  Superintendent  of  Public 
Schools. 

"MANCHESTER,  BURR  SEMINARY,  October 30, 1850. 
"DR.  LAMBERT: 

"  DEAR  SIR,— I  have  attentively  and  for  practical  purposes  examined  your  books 
on  Physiology,  more  particularly  the  Second  Book,  which  I  consider  better  than  any 
with  which  I  am  acquainted,  to  be  used  as  a  school  book,  on  the  subjects  of  which  it 
treats.  The  intelligent  and  faithful  teacher  cannot  fail  to  make  it  an  interesting  and 
valuable  branch  of  study.  Many  excellences  might  be  named ;  I  will  specify  but 
one,  as  rare  :  the  discriminating  language  in  which  the  questions  are  put  to  the  pupil. 
I  should  be  pleased  to  have  this  book  introduced  into  the  schools  of  this  town,  and  to 
hear  that  its  use  was  general.  I  think,  also,  that  your  book  will  be  found  exceedingly 
interesting  to  the  general  reader,  and  be  used  with  great  advantage  as  a  reference 
book. 

"  Yours  truly, 

«W.  A.  BURNHAM." 


PI.1 


Fig,  4. 


Zig.l 


Fig. 


fig.  /. 


Fig.   J. 


II. 


PI.  5. 


POPULAR 


ANATOMY  AND  PHYSIOLOGY, 


ADAPTED  TO  THE  USE  OF 


STUDENTS  AND  GENERAL  READERS. 


BY 


frof. 


T.  S.  LAMBERT,  M.  D., 

.  of  Anatomy  and  Physiology  in  Pittsfield  (Young  Ladies')  Institute,  Brooklyn 
(Qreenleaf  's  Young  Ladies')  Institute  ;  Author  of  Notes  to  Erasmus 
Wilson  on  the  Skin,  Popular  Treatise  on  Bathing,  etc. 


WITH  ONE   HUNDRED  AND   FIFFY   WOOD-CUT   AND   BEAUTIFUL    LITHOGRAPHIC 
DESCRIPTIVE   ILLUSTRATIONS. 


PORTLAND: 
SANBORN  &  CARTER. 

NEW  YORK:  LEAVITT  &  CO. 
1851. 


V 


BIOLOGY 

LIBRARY 

G 


Entered,  according  to  act  of  Congress,  in  the  year  1849,  by 
T.  S.  LAMBERT, 

In  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for  the  Southern  District 
of  New- York. 


MULLER     AND     LIEBIG, 

AUZOUX,  MAGENDIE,  FLOURENS,   ORFILA,   AND   CRUVELHIER, 

PEREIRA,  WATSON,  WILSON,  CARPENTER,  LISTON, 

AND  MARSHALL  HALL, 

As  most  distinguished  ornaments  of  their  profession  and  humanity; 


JOHN    AND    SIR    CHARLES    BELL, 
COOPER,  LAWRENCE,  GOOD,  HOME,  RICHERAND,  AND   LAENNSO, 

(Who  though  dead  yet  live,) 
As  those  whose  writings  have  given  me  the  greatest  pleasure  and  much  instruction  ; 

AND   TO   THE 
MEDICAL    PROFESSION   OF   THIS    COUNTRY, 

Whose  members  as  a  body  I  love  and  respect,  from  too  many  of  whom  to  particu- 
larize I  have  been  the  recipient  of  courtesy,  and  from  whose  works  and  conversation  a 
rich  store  of  knowledge  has  been  gathered,  and  used  with  profit  in  the  following 
pages; 

THIS    BOOK 

S»  tespectfultB  trcDfcatett, 

With  the  intention  of  rendering  honor  where  it  is  so  richly  due,  and  as  the  only 
token  of  his  admiration  and  indebtedness  which  can  yet  be  presented  by 

THE   AUTHOR 


CONTENTS. 


•tip 

ADDRESS  TO  THE  READER,       .  >    •     •  •  •  .  .9 

INTRODUCTION,      .  .          y         ",  •        .  •  Sr  '-3 

BOOK  I. 

THE  FIRST  CLASS  OF  ORGANS. 
CHAPTER  I. 

THE   ORGANS   OF   VOLUNTARY   MOTION- 

SEC.  1. — The  Bones,  Cartilages,  and  Ligaments,        .  .  17 

2.— Muscles,  Tendons,  &c.,  .  .  .  .50 

3.— The  Brain  and  Nerves,        .         ?  ..."  . 

CHAPTER    H. 

THE  ORGANS  OF  SENSATION  OR  FEELING. 

SEC.  1. — Sensations,         .            .            ..  ...        .    ;    '        .      112 

2. — Objects  producing  Sensations,           .  .           V           119 

3.— The  Organs  of  Sense,  '.'        V*  .            .                   122 

4. — The  Nerves  of  Sensation,     .           V-  •    *        .            195 

5. — The  Brain  as  an  organ  of  Sensation,  .            .  '         .      205 

6. — The  Mind  in  respect  to  Sensation,    .  v.:          .             211 

7. — Concluding  Remarks  on  the  Organs  of  Sensation,  .      218 

CHAPTER   HI. 

FHE  MIND   AND   ORGANS   WITH   WHICH   TO  THINK. 

SEC  .  1.—  The  Brain,         Y       •  V  '    •    v"       ;V  *  ,    -224 

2.— The  Mind,  .  240 


CONTENTS. 

BOOK  II. 

SECOND  CLASS  OF  ORGANS. 

FAOB 

GEKERAL  OBSERVATIONS,         .  .  243 

CHAPTER   1. 

THE   DIGESTIVE   ORGANS. 

Ssc.  1.— The  Mouth,      \*      *V          "V  ^     ' '.    <  -      254 

2— The  Stomach,  .  .  273 

3 The  Second  Stomach,  Liver,  Pancreas,  Spleen,  Colon,  &c.,  317^ 

CHAPTER    H. 

THE   CIRCULATORY   ORGANS. 

SEC,  1.— The  Heart,         .  ,•  -  .  •      335_~ 

2. — The  Bloodvessels  and  Lymphatics,   .  .  .  340- 

3.— Causes  of  the  Circulation,        i'i>  .  .  .      353-- 

CHAPTER   in. 

THE  RESPIRATORY   ORGANS. 

SEC.  1.— The  Air  Passages,       *•:'*"                     .  .363 

2. — Circulation  of  the  Blood  about  the  Air  Passages,      .  365 

3. — Inhalation  and  Exhalation  of  Air,      .-..^       . .  \\  •  ••   ',  *:    366 

4. — Action  of  the  Blood  and  Air  upon  each  other,      ..  .«,.;.  370 

CHAPTER  IV.       **  5 

THE  VOICE. 

SEC.  1.— Expulsion  of  Vocal  Air,    .  f A    ^* .          V  382 

2._Modifiers  of  Sound,      '. -;  -  :  ^  K    ;  "+  ''    c    .  .      383 

3.— The  Larynx,  .          /  .  .          »yi'fi   *fct&         386 

CHAPTER  V. 

ORGANS   OF   EXCRETION. 

SEC.  1. — The  Second  Stomach,  Colon,  &c.,  O^\  *      391 

2.— The  Liver,    .           ^h--        .            .           4        ^    ..  393 

3.— The  Lungs,    ....         . :-,         .  .        i-»";:  .      395 

4—The  Kidneys,          . .            .            .        :    I         :  .  396 

5.— The  Skin,           ,j<      :^;-Urj  .           .  .397 
CHAPTER  VI. 

THE    ORGANIC    NERVOUS   SYSTEM. 

General  Observations,  .  •  .  .  .  406 


DESCRIPTION  OF  LITHOGRAPHIC  PLATES. 

PI.  1,  Fig.  1.  Represents  the  muscles  and  tendons  a*  they  appear  when  the  skin  is 
removed,  except  that  the  external  muscles  are  also  rerao^  ed  from  the  left  side ;  they  are 
ehown  upon  the  right  side.  The  direction  of  the  stripes  shows  the  direction  in  which 
the  muscles  and  parts  of  the  muscles  contract,  and  of  course  the  direction  in  which  they 
have  a  tendency  to  produce  motion. 

Fig.  2.  The  bones  of  the  ankle  and  the  internal  muscles  of  the  lower  part  of  the  leg. 
The  tendon  of  84  is  seen  in  the  most  beautiful  manner,  turning  around  the  outer  joint 
of  the  ankle  and  under  the  foot,  beneath  which  it  passes  to  be  attached  to  the  bone  back 
of  the  great  toe. 

Fig.  3. — Back  portion  of  the  jaw,  the  ear ;  and,  36,  temporal  muscle  attached  to  a 
prominent  point  of  the  jaw,  K. 

Fig.  4. — Lower  portion  of  the  chest,  with  the  front  portion  of  the  ribs  removed  to 
show  ihe  diaphragm  7,  below  which  is  seen  a  portion  of  the  upper  part  of  the  abdomen, 
with  its  front  wall  and  organs  removed.  2,  3,  The  back  lower  edge  of  the  diaphragm, 
the  "pillars"  of  which  are  seen  attached  to  the  back-bone.  The  front  lower  edge  of 
the  diaphragm  is  lower  than  here  represented,  especially  at  the  side. 

PI.  2,  Fig.  1.— View  of  the  external  muscles  of  the  back,  except  upon  the  left  side, 
where  the  "  middle"  layer  of  muscles  is  brought  to  view. 

Fig.  2. — Internal  muscles  of  the  back. 

Fig.  3.,  4.— Muscles  and  tendons  beneath  the  foot. 

PI.  3,  Fig.  1.— Front  half  of  the  chest  and  abdomen  removed,  presenting  the  organs  of 
those  parts  as  they  would  appear  in  front,  during  life.  They  would  not  appear  thus  how- 
ever, when  the  body  is  opened,  as  they  would  flatten  and  change  their  position,  hence  it 
must  be  kept  in  mind  that  the  organs  are  not  flat,  but  project  toward  the  observer,  in  the 
centre,  rounding  back  at  the  sides,  as  the  body  does  when  viewed  in  front.  1,  Right 
lung.  2,  Left  lung.  3,  Diaphragm  which  arches  up  under  the  lungs,  its  front  and 
lower  edge  being  attached  to  the  front  and  lower  edge  of  the  ribs  as  seen.  4,  The 
liver,  which  lies  up  under  the  diaphragm  in  such  a  manner  that  if  a  knife  should  be  thrust 
through  where  the  dotted  line  from  3  terminates,  the  liver  would  be  wounded.  5,  Stom- 

-  up  under  the  lower  curvature  of 
food.  6,  Colon,  where  it  passes 
the  three  longitudinal  bands  of 
muscles  which  contract  the  colon  into  pouches,  as  seen.  7,  The  second  stomach,  the 
commencement  of  which  is  seen  in  some  of  the  woodcuts  dispersed  through  the  work. 
8,  Front  surface  of  a  small  part  of  the  spleen,  the  chief  part  of  which,  when  the  breath 
is  thrown  out,  is  above  and  back  of  the  part  seen.  9,  The  base  of  the  gall  bladder  which 
lies  forward  10  the  edge  of  the  liver,  the  upper  part  being  found  underneath  the  liver, 
between  it  and  the  colon  and  stomach. 

Fig.  2.— Ideal  view  of  the  left  lung  2,  cut  from  side  to  side  perpendicularly  throueh 
the  middle.  The  right  lung  is  seen  contracted,  as  when  the  chest  is  opened.  The 
heart  is  between  them.  The  object  is  to  convey  the  idea  that  the  air  inhaled  passes 
through  the  windpipe  and  its  divisions  1, 1,  into  air-cells,  and  that  the  blood  passes  into 
the  lungs  through  the  artery  6.  from  the  right  heart  4,  and  after  the  blood  has  passed  round 
the  air-cells  and  been  acted  upon  by  the  air,  comes  back  to  the  left  heart  5,  through  the 
vessels  7,  of  which  there  are  two,  leaving  the  lungs. 

Fig.  3. — A  greatly  magnified  view  of  the  net- work  of  capillary  bloodvessels  upon  the 
sides  of  the  air-cells.  It  is  not  so  extensive  as  would  in  fact  cover  the  sides  of  a  mus- 
tard seed.  The  blond  passes  in  through  one  set  of  vessels  and  passes  back  through  an- 
other, as  the  colors  exhibit. 


DESCRIPTION  OF  LITHOGRAPHIC  PLATES. 

PL  4,  Fig.  1.— The  red  vessels  represent  the  arteries  of  the  entire  body  branching  to 
the  various  parts  of  the  system,  not  precisely  after  the  manner  of  the  arteries  of  tho 
body,  but  sufficiently  accurate  to  convey  a  general  idea.  The  blue  vessels  represent 
the  veins. 

Fig.  2.— R,  Right  heart.  L,  Left  heart,  from  which  the  red  vessels  lead  the  blood 
into  the  capillaries  C,  C,  of  the  body,  from  which  it  comes  back  to  the  right  heart,  pass- 
ing thence  into  R,  L ;  L,  L,  the  capillaries  of  the  lungs,  thence  back  to  L,  left  heart. 

Fig.  3.— Hearts  and  vessels  separated  from  each  other. 

Fig.  4.— Portal  system  of  vessels.  1,  Spleen.  2,  Pancreas.  3,  Portion  of  duodenum. 
4,  Gall  bladder  turned  up,  as  better  seen  in  woodcut.  5,  Tube  or  duct,  from  the  gall 
bladder.  6,  Duct  from  the  liver.  7,  8,  Veins  from  the  second  stomach ;  9,  those  from 
the  stomach,  which  with  those  from  the  spleen  and  pancreas  unite  to  form  the  portal 
vein  10,  which  divides  and  subdivides  in  the  liver. 

PI.  5,  Fig.  l.-B,  Candle  giving  off  blue  light.  Y.  Candle  giving  yellow  light.  R, 
Candle  giving  red  light.  In  all  cases  the  light  passes  from  a  candle  in  all  directions,  but 
only  so  many  rays  as  would  enter  the  opening  a,  are  represented.  Such  rays  passing 
through  the  opening  a,  fall  upon  the  very  much  magnified  commencing  points  of  the 
nerve  1.  The  light  from  no  two  candles  is  seen  to  act  on  any  of  the  same  nerves.  2, 
Outer  coats  of  the  eye.  3,  Pigmentum  nigrum.  Neither  this  nor  any  of  the  succeeding 
figures  are  intended  to  convey  any  correct  idea  of  the  eye,  except  as  it  respects  the  ac- 
tion of  light  thrown  upon  the  nerves. 

Fig.  2.— The  light  is  seen  passing  through  a  lens,  by  the  action  of  which,  the  entire 
yellow  light  passing  through  the  pupil  a,  is  made  to  act  on  one  point ;  the  same  is  also 
true  of  the  light  from  R  and  B. 

Fig.  3.— R,  Y,  B,  As  heretofore.  But  in  this  case  the  lens  has  not  acted  upon  tho 
light  sufficiently  to  cause  it  to  act  on  a  single  nerve,  but  the  red  light  acts  over  the 
nerves  between  4  and  6,  the  yellow  light  acts  on  the  nerves  between  5  and  7,  and  the 
blue  .light  on  the  nerves  between  6  and  8.  The  nerves  between  4  and  5,  and  between  7 
and  8,  are  acted  on  by  one  kind  of  light  only,  the  nerves  between  5  and  6  by  both  red 
and  yellow  (orange),  and  the  nerves  between  6  and  7  by  blue  and  yellow  (green).  This 
is  the  case  with  long-sighted  people.  Most  old  people  have  indistinct  vision  from 
this  effect  being  produced  by  the  insufficient  action  of  the  parts  through  which  light 
passes  to  the  nerve. 

Fig.  4.— R,  Y,  B,  As  before.  In  this  case  the  light  is  acted  upon  so  powerfully  that 
it  is  bent  to  points  or  foci  before  it  reaches  the  nerve ;  it  passes  the  point  or  focus  there- 
fore, and  when  it  reaches  the  nerves,  the  red  light  acts  over  the  space  between  4  and 
6,  the  yellow  light  upon  the  nerves  between  5  and  7,  the  blue  light  on  the  nerves  be- 
tween  6  and  8,  and  the  same  cause  of  confusion  exists  as  in  case  of  Fig.  3 ;  that  it  is 
BO,  is  evident  by  bringing  a  thing  so  near  to,  and  removing  it  so  far  from  the  eye,  that  it 
becomes  indistinct ;  the  sensation  is  similar  in  each  case.  So  also  when  the  locus  of  a 
microscope  or  telescope  is  brought  toward  or  removed  from  the  eye.  the  effect  is  simi- 
larly indistinct.  This  is  the  near-sighted  eye. 

Fig.  5. — A,  B,  Are  two  rays  of  different  colored  light  passing  through  the  hole  2,  in 
partition  1, 1,  and  acting  on  the  end  of  one  nerve  D,  producing  the  effect  of  compound 
light. 

Fig.  6.— A,  B,  Two  rays  of  different  colored  light  acting  on  two  nerves,  a  simple 
effect  being  produced  on  each  nerve. 

Fig.  7. — W,  a  ray  of  white  light  passing  through  the  pin-hole  a,  and  bent  upward  aa 
it  is  passing  through  the  prism  P.  The  blue  light  is  bent  the  most,  the  yellow  more 
than  the  red  but  not  as  much  as  the  blue,  while  the  red  is  bent,  but  less  than  the  yellow 
and  blue. 

Fig.  8.— The  three  colors  which  compose  white  light  upon  a  small  card.  If  it  be 
whirled  rapidly  on  a  pin  thrust  through  the  centre,  the  light  from  each  part  will  act  on 
the  same  nerves,  and  the  card  will  appear  white. 

Fig.  9. — A  mirror  reflecting  all  kinds  of  light. 

Fig.  10.— A  black  object  not  reflecting  any  light. 

Fig.  11,  reflecting  only  red.    Fig.  12,  reflecting  only  yellow.    Fig.  13,  only  blue. 


ADDRESS  TO  THE  READER. 

EVERY  one  desires  to  be  happy.  It  seems  to  me  a  high 
degree  of  happiness  can  be  obtained  by  every  person  if  he 
will  constantly  ask  himself  two  questions :  1st.  What  can 
he  do  to  make  others  happier.  2d.  What  is  the  cause  of 
any  effect  he  sees.  The  first  will  improve  his  disposition, 
the  second  will  cultivate  his  intellect.  That  increased  ami- 
ability and  humanity  will  render  a  person  happier,  needs  no 
argument  to  prove ;  while  the  instant  a  person  begins  to  seek 
the  why  and  wherefore  of  things,  he  begins  to  acquire  know- 
ledge, so  satisfactory  and  delightful  to  the  mind,  that  it  is 
stimulated  to  farther  investigations,  and  soon  rewarded  by 
the  most  profitable  results, — not  the  least  of  which  will  be  an 
inquiring  mind.  It  seemed  to  me,  I  could  answer  the  first 
question  in  no  way  so  well  as  by  writing  the  present  volume. 
In  thus  rendering  others  happier,  my  own  happiness  will  be 
increased  in  three  ways:  by  the  pecuniary  compensation 
received,  by  the  esteem  of  community,  and  by  the  conscious- 
ness that  the  book  is  a  public  benefit.  That  the  greatest 
effect  may  be  produced  in  each  of  these  ways,  no  pains  have 
been  spared  to  make  the  book  valuable.  That  it  has  real 


10  ADDRESS  TO  THE  READER. 

faults,  there  is  not  the  slightest  doubt.  Many  things  also  which 
displease  some,  will  please  others.  Some  things  appear  as 
blemishes  to  me,  which  have  been  allowed  to  remain  in  ac- 
cordance with  the  opinion  of  some  whose  judgment  was  re- 
spected. It  was  intended  to  meet  the  general  approbation  of 
many,  and  cannot  therefore,  in  every  particular,  satisfy  each 
person,  who  will  it  is  hoped  consider,  that  our  best  friends 
have  faults,  on  account  of  which  many  times  we  love  them 
the  better,  as  they  do  not  seem  to  be  more  perfect  than  our- 
selves. That  the  treatise  may  render  others  happier,  the 
object  has  been  to  communicate  satisfactory  knowledge  upon 
the  principle  that, 

"  To  please,  is  the  first  step  towards  instructing  j" 

and  with  the  importance  of  the  second  question  constantly  in 
mind,  to  wit :  It  has  been  the  constant  endeavor  to  induce  the 
reader  or  student  to  think,  to  inquire  into  causes,  to  lead  him 
on  step  by  step  to  the  fruits  of  knowledge ;  that  he  may  be 
practically  convinced,  that  it  can  be  usefully  applied  to  alle- 
viate the  ills  of  life  and  increase  its  blessings.  To  know  the 
success  with  which  this  has  been  accomplished,  would  deter 
mine  in  the  author's  mind  the  value  of  the  book,  to  a  great 
degree.  It  is  therefore  hoped  that  his  opinion  will  never 
be  considered  decisive  upon  any  point.  The  purported 
truths  here  set  forth,  are  of  the  highest  interest  and  value, 
if  truths ;  they  are  susceptible  of  illustration  and  support, 
or  of  refutation  and  condemnation,  in  the  every-day  oc- 
currences of  every  person's  life,  And  so  much  confidence 


ADDKESS  TO  THE  READER.  11 

is  placed  in  the  correctness  of  the  views  brought  forward,  that 
it  is  believed  when  they  are  thoroughly  tested,  the  causes  of 
effects,  and  the  reasons  for  the  beautiful  operations  taking 
place  in  the  system,  will  be  so  clearly  seen,  that  natural 
curiosity  will  be  ripened  into  enthusiastic  inquiry,  and  a 
spirit  of  investigation  produced  which  will  spurn  the  dicta- 
tion of  any  writer,  and  acknowledge  but  one  teacher,  TRUTH. 
Questions  have  not,  therefore,  been  connected  with  the 
present  volume,  but  have  been  placed  in  a  separate  book, 
because,  when  questions  are  in  the  hands  of  the  scholar,  he 
too  frequently  merely  commits  a  clause  which  answers  the 
question ;  and  again,  as  will  be  seen  by  looking  at  the  book 
of  questions,  many  are  of  such  a  nature  that  the  answer  is 
not  in  the  text,  but  is  intended  to  cause  the  scholar  to  think  ; 
while  as  sometimes  teachers,  and  frequently  parents  who 
would  wish  to  instruct,  might  not  feel  inclined  to  take  the 
responsibility  of  deciding  on  an  answer,  a  correct  one  is 
given  with  the  question,  and  various  illustrations  of  the  text, 
which  might  not  otherwise  suggest  themselves  to  teacher, 
parent  or  scholar ;  many  teachers  also  prefer  to  ask  their 
own  questions,  suggested  by  the  text.  As  the  treatise  is 
designed  to  be  a  book  for  general  reading  as  well  as  a  text- 
book for  students,  it  was  thought  an  advantage  to  have  the 
questions  optional ;  though,  being  separate,  many  facts  can 
be  communicated  and  suggested  by  them  which  could  not 
consistently  be  introduced  in  the  text,  and  will  render  it  a 
pleasure  for  the  general  reader  to  notice  the  questions. 
With  them  the  parent  can  with  perfect  ease  teach  his  child 
the  important  truths  of  this  science,  at  an  early  age,  there 


12  ADDRESS  TO  THE  READER. 

being  but  one  suggestion  to  make ; — that  the  child,  older  or 
younger,  receive  very  short  lessons.  A  lesson  containing 
one  practical  truth  will  be  sufficient ;  this  being  so  illustrated 
and  applied,  which  the  questions  will  do,  that  it  will  become 
part  of  the  student's  nature  to  be  actuated  by  the  grand  prin- 
ciples which  the  Creator  has  appointed  to  govern  the  physi- 
cal welfare  of  man.  These  truths,  these  principles,  he 
should  learn  so  thoroughly,  by  having  them  frequently 
brought  before  the  mind  and  fully  illustrated,  that  he  shall  be 
actuated  by  them  unthinkingly,  and  entirely  forgetful  of  their 
source,  consider  them  merely  as  indubitable,  and  teach  them 
to  others  as  truths,  the  observance  of  which  bestows  the 
greatest  physical  blessings.  That  thus  the  knowledge  which 
it  is  believed  this  book  can  impart,  may  be  the  means  of  add- 
ing to  the  happiness  of  many  who  shall  never  hear  of  the, 
name  or  existence  of  the  author,  is  my  sincere  wish. 
New-York,  Nov.  1,  1849. 


THE 

ANATOMY  AND  PHYSIOLOGY 


OF  THE 


HUMAN  SYSTEM. 


M   INTRODUCTION. 

1.  The  object  of  the  following  pages  is,  to  prove  that 
Beauty,  Health,  Strength,  and  Length  of  Days,  mental  and 
physical,   depend  upon  observing  certain  Laws — to  unfold 
and  illustrate  these  Laws,  and  enforce  the  importance  of  obey- 
ing them. 

2.  This  will  be  attained  by  imparting  the  knowledge 
establishing  these  laws,  and  by  examining  the  four  sources 
from  which  it  is  derived. 

3.  First.  The  structure  of  the  Human  System — HUMAN 
ANATOMY. 

4.  Second.    The  uses  of  the  Human  Organs — HUMAN 
PHYSIOLOGY. 

5.  Third.  The  concurring  testimony  of  all  men — UNA- 
NIMOUS EXPERIENCE. 

6.  Fourth.  The  particular  experience  of  each  person — 
PERSONAL  EXPERIENCE. 

7.  Three  difficulties  attend    an    investigation  of  these 
sources  of  knowledge : — 

8.  The  first  arises  from  want  of  proper  means  to  see  and 


14  INTBODUCTION. 

dissect  minute  parts  of  the  body,  and  examine  the  delicate 
operations  that  take  place  therein. 

9.  The  second  is  owing  to  the  infrequency  of  opportuni- 
ties for  observing  the  interesting  phenomena  of  internal  life. 

10.  The  third  and  greatest  difficulty  is  found  in  recon- 
ciling conflicting  testimony,  and  sifting  from  it  all  prejudice 
and  bias. 

11.  However,  a  doubt  will  but  rarely  exist  if  the  testi- 
mony from  each  source  be  obtained  upon  any  point.     For 
the  testimony  from  three  sources  agreeing,  it  would  correct 
the  contradictory  testimony  from  the  other. 

12.  The  knowledge  from  the   fourth  source  being  per- 
sonal, can  only  be  obtained  by  learning  the  experience  of 
each  person,  when  the  laws  peculiar  to  him  may  be  estab- 
lished. 

13.  The  laws  based  upon  the  knowledge  drawn  from  the 
first  three  sources  are  to  be  learned  and  observed  by  all, 
since  they  are  universal  and  invariable.      They  may  with 
propriety,  therefore,  be  laid  down  in  books,  and  profitably 
acquired  therefrom. 

14.  To  do  this  most  successfully  and  concisely,  man  may, 
firstly,  be  considered  under  the  heads  of  Mind  and  Body. 

15.  The  Mind  is  that  which  thinks,  feels,  and  causes 
voluntary  action  ;  is  properly  the  man. 

16.  The  Body  is  a  beautiful  piece  of  mechanism,  com- 
posed of  many  parts,  adapted  to  the  use  of  the  mind,  with 
which  the  mind  thinks,  feels,  and  acts. 

17.  Mind  and  body  are  so  intimately  connected  with  each 
other,  and  so  powerfully  influence  each  other,  they  cannot  be 
considered  distinctly.    The  state  of  one  always  affects  that  of 
the  other.     The  tears  flow  profusely  when  the  mind  is  over- 
come with  grief.      Anger  reddens  the  cheek,  which  is  paled 
by  fear.      While,  vice  versa,  too  much  food  unfits  a  person 
for  study  ;  but  wholesome  food,  and  a  healthy  digestion  of 


INTRODUCTION.  15 

it,  give  vigor  to  the  mind  and  life  to  the  spirits.     As  Tupper 
so  eloquently  writes, — 

"  The  best  cosmetic  is  a  holy  conscience  f 
or  as  Thomson, — 

"  E'en  from  the  body's  purity,  the  mind 
Receives  a  secret  sympathetic  aid." 

18.  Indeed,  whatever  elevates  the  intellect,  regulates  the 
passions,  sweetens  the  disposition,  or  cultivates  the  affections, 
tends  to  develope  beauty,  preserve  health,  increase  strength, 
and  prolong  life. 

19.  On  the  other  hand,  ignorance,  ungoverned  temper, 
moroseness,  and  sensuality,  will  despoil  the  fairest  intentions 
of  nature,  develope  disease,  enervate  the  system,  and  produce 
untimely  death. 

20.  This  is  not  the  place  to  treat  on  morals ;  yet  it  may 
be  observed,  that  our  Quaker  friends  are  not  a  little  indebted 
for  their  celebrated  complexions,  good  health,  and  long  lives, 
to  the  healthful  moral  influences  with  which  they  surround 
themselves. 

21.  So  much  do  the  manifestations  of  the  mind  depend 
upon  the  state  of  the  body,  some  have  too  hastily  concluded, 
mind  was  only  the  necessary  result  of  action  of  certain  parts 
of  the  body. 

22.  An  attempt  will  be  made  in  various  parts  of  this 
work,  to  show  clearly,  that  the  distinction  between  mind  and 
body  is  correct. 

23.  As  they  depend  so  intimately  upon  each  other,  if  one 
be  considered,  the  other  is  necessarily  involved ;    and  it  is 
enough,  therefore,  that  especial  attention  be  given  to  one ; 
and  in  the  present  work,  it  is  our  duty  to  take  the  body  for 
the  particular  topic  of  discourse. 


16  INTRODUCTION. 

24.  Of  the  body,  two  classes  of  organs  will  be  consider- 
ed.     For  though  it  is  a  whole,  and  each  part  affected  by 
every  other  part,  yet — 

25.  One  class  of  organs  is  used  with  which  to  think,  feel, 
and  act ; 

26.  Another,  to  keep  the  first  class,  and  also  itself,  in  good 
condition. 

27.  The  first  class  may  be  subdivided  into  three  classes 
of  organs,  which  include — 

28.  1st.  The  brain,  with  which  to  think  ; 

29.  2d.  The  organs  of  sense,  nerves,  and  brain,  with 
which  to  feel ; 

30.  3d.  The  bones,  cartilages,  ligaments,  muscles,  nerves, 
brain,  and  some  minor  organs,  with  which  to  act. 

31.  The  utility  of  the  second  class  of  organs  will  be 
better 'perceived  after  the  first  class  has  been  described. 

32.  The  propriety  of  dividing  my  subject  into  two  books 
will  now  be  seen,  and  the  subdivisions  of  the  first  book  will 
be  anticipated. 


BOOK  I. 

THE   FIRST  CLASS   OF   ORGANS. 


CHAPTER  I. 

THE  ORGANS   OF  VOLUNTARY  MOTION. 

SECTION  1. — The  Bones,  Cartilages,  and  Ligaments. 

33.  These  parts  form  the  framework    of  the  human 
system. 

34.  The  use  of  this  framework  is  to  give  form  to  the 
body,*  to  support  the  soft  parts  in  their  proper  positions,  to 
protect  some  of  them,  to  allow  motions  of  one  part  upon  an- 
other,  and  of  the  whole,  from  one  place  to  another. 

35.  To  fulfil  these  requirements  the  frame  must  be  very 
strong,  of  sufficient  size  to  admit  the  attachment  of  the  nu- 
merous soft  parts,  yet  very  light ;  it  must  be  composed  of 
many  pieces,  very  strongly  united,  yet  in  such  a  way  as  to 
allow  the  desirable  motions,  with  the  least  friction. 


*  Since  the  general  form  depends  upon  the  skeleton,  every  lady  de- 
siring to  possess,  or  desiring  her  child  to  possess  a  fine  form,  will  feel 
exceedingly  interested  to  know  all  that  can  be  learned  in  respect  to  the 
bones,  and  anxious  to  do  every  thing  which  will  perfect  them. 


18 


ORGANS  OF  VOLUNTARY  MOTION. 
Fig.  1.— Skeleton,  Front  View. 


[CHAP.    I. 


36.  Composed  of  bone,  cartilage,  ligaments,  with  some 
minor  adjuncts,  the  frame  is  perfect  in  all  these  respects ;  I 
know  not  which  to  admire  the  most — the  perfection  of  the 
bones,  the  elasticity  of  the  cartilage,  or  the  strength  and  beau- 
tiful  arrangement  of  the  ligaments.  Our  hearts  are  moved 
with  adoration  when  we  read  the  handiwork  of  the  Creator 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS. 

Fig.  2.-— Skeleton,  Back  View. 


19 


in  the  superlative  form  and  texture  of  the  skull ;  but  not  less 
are  they  moved  with  gratitude  as  we  view  the  cushion-like 
cartilages  supplied  to  the  back,  or  the  powerful  bands  which 
unite  all  parts  into  one. 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  3.— Skeleton,  Side  View. 


37.  The  bones  are  adapted  to  their  purpose  by  their  com- 
position,  form,  and  being  hollow. 

38.  They  are  composed  of  two  substances ;  one  soft,  the 
other  hard.     The  two  and  their  nature  can  be  easily  per- 
ceived, if  two  similar  bones  be  placed,  one  in  fire,  and  the 
other  in  some  diluted  mineral  acid.     In  a  short  time,  if  taken 
out,  though  both  have  the  same  form  as  before,  one  will  bend, 
indeed  may  be  tied  in  a  knot  (Fig.  4),  the  other  will  crumble 
like  chalk,  the  acid  having  removed  the  hard  or  earthy  por- 
tion, and  the  fire  destroyed  the  softer  or  cartilaginous  portion. 
The  form  of  each  being  the  same  as  before  the  experiment, 
it  will  be  seen  that  the  hard  and  soft  parts  are  intimately 
blended  throughout  the  bone.* 

*  Sometimes,  by  disease  or  some  cause,  the  hard  part  is  removed  from 
the  bone  during  life,  and  the  bone  thus  affected  will  bend  in  any  direction, 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  21 

Fig.  4. 


39.  The  proportions  of  the  two  parts  to  each  other  vary 
much  under  different  circumstances. 

40.  In  earliest  life  the  soft  parts  only  would  be  found ;  at 
a  certain  time  a  few  particles  of  the  hard  part  are  deposited 
in  one  or  several  points  of  the  soft  part,  called  "  points  of  os- 
sification ;"  additions  are  then  made,  till  throughout  the  soft 
part  the  hard  part  would  be  found,  but  in  very  small  propor- 
tion ;  this,  however,  is  gradually  increased  by  fresh  additions 
throughout,  till  at  last  the  bone  has  sufficient  strength  to  bear 
the  weight  of  the  child.     The  hard  or  earthy  part  continues 
to  increase  till  old  age,  in  mature  years  giving  the  bones  the 
greatest  degree  of  strength,   and  in  advanced  life  making 
them  extremely  brittle. 

41.  In  some  bones  the  deposit  is  made  much  earlier  and 
more  rapidly  than  in  others  of  the  same  body. 

42.  In  some  children  also  than  in  others. 

43.  These  statements  will  account  for  the  bones  of  chil- 
dren bending  easily  and  breaking  with  difficulty,  while  those 
of  old  people  break  easily  and  do  not  yield  to  pressure.     The 

and  people  will  say  the  bone  is  gone.  I  have  seen  one  such  case,  the 
tipper  arm  bone  of  a  young  man,  18  years  old :  the  cause  I  could  not 
learn ;  the  ultimate  effect  I  have  not  yet  heard.  In  other  respects  he 
seemed  to  enjoy  usual  health . 


22  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

predominance  of  the  soft  part  is  also  one  reason  why,  if  the 
bones  of  children  be  broken,  they  unite  readily,  while  in  old 
people  the  predominance  of  the  earthy  part  retards  the  pro- 
cess of  restoration  and  sometimes  prevents  it. 

44.  It  would  be  inferred,  that  a  child  does  not  walk  ear- 
lier because  it  is  not  fitted  to  do  so ;  therefore  no  pains  should 
be  taken  to  teach  a  child  to  walk  by  using  standing-stools  or 
the  like.    Even  leading  a  child,  or  standing  a  child  upon  its 
feet  must  be  wrong ;  placing  a  child  in  one  position,  long  or 
often,  should  be  avoided  ;  so  also,  placing  or  carrying  a  child 
in  such  a  position,  that  much  weight  shall  be  borne  upon  one 
part  of  the  body,  cannot  be  right. 

45.  It  must  be  evident  that  the  heavier  a  child,  the  greater 
the  effect  and  necessity  for  care. 

46.  Is  it  not  probable,  also,  that  if  a  child  be  backward 
it  is  for  some  good  reason,  and  will  it  not  prove  injurious  to 
attempt  to  teach  the  child  to  walk  ?* 

47.  That  this  hard  part  may  be  deposited,  it  must  be  fur- 
nished  to  the  child  in  its  food.     Now,  it  must  be  evident  that 
milk  contains  this  substance,  as  it  has  been  designed  by  the 
Creator  for  the  use  of  young  animals,   and  because  we  see 
the  bones  of  animals  become  strong  and  good,  when  nothing 
but  milk  is  used  as  food.      As  the  works  of  the  Creator 
are  so  perfect,  can  it  be  best  to  go  contrary  to  his  evident  in- 
tentions,  and  feed  a  child  with  any  thing  but  milk  ?      In- 
deed it  is  not  impossible  that  chicken-breasted  and  other  defor- 
mities, the  result  of  too  soft  bones,  may  be  in  part  or  wholly 


*  I  do  not  believe  that  a  child  can  be  advanced  one  day  by  attempts 
at  teaching.  It  seems  to  me  that  a  child  walks  as  other  animals,  actu- 
ated by  an  instinct,  and  will  of  its  own  accord,  and  untaught,  walk  as  soon 
as  it  should,  as  soon  as  it  can.  Some  may  say  that  exercising  a  child  will 
give  it  strength  earlier  ;  but,  with  the  delicate  muscles  of  the  child,  over- 
exercise,  rather  than  want  of  it,  is  to  be  feared  ;  and  the  bow-legs,  chick- 
en-breasts, and  other  deformities  so  common,  show  that  the  other  animate 
are  more  favorably  situated  in  this  respect  than  the  human  species. 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  23 

produced  by  feeding  the  child  with  arrow-root  and  the  like, 
especially  as  it  will  be  hereafter  shown  that  such  things 
tend  to  increase  the  weight  of  the  child  by  fat,  an  end  not 
desirable,  and  cannot  strengthen  the  bones,  which  is  of  pri- 
mary importance. 

48.  The  forms  of  the  bones  are  so  various,  and  the  bones 
are  so  exceedingly  irregular,  it  would  at  first  seem  there 
could  be  no  general  plan  by  which  they  were  all  made. 
Quite  the  reverse  opinion  will  be  formed  on  examination. 

49.  The  numerous  indentations  upon  the  surface  of  the 
bones,  are  evidently  for  the  purpose  of  obtaining  a  greater 
extent  of  surface  for  the  attachment  of  soft  parts  ;  the  promi- 
nences serve  the  same  purpose,  and  also  act  as  levers  (Fig.  5). 
Many  times  a  ridge  is  seen  upon  a  bone  (Fig.  6),  which  adds 
greatly  to  its  strength  and  scarcely  any  thing  to  its  weight. 

Fig.  5.  Fig.  6. 


Fig.  5.— r,  A  resistance,  p,  A  power  acting  on  the  lever  (r  p),  of  which  the  skul. 
is  a  part.  From  r  to  the  skull,  ana  from  p  to  the  skull,  represent  prominences  upon 
the  bones  ;  the  longer  these  are,  the  greater  the  effect  of  any  force  acting  upon  them. 

Fig.  6.— Section  of  a  bone,  with  a  ridge  (B)  to  strengthen  it.  A,  The  hollow  of  the 
bone. 

50.  If  the  bones  be  examined  in  almost  every  exposed 
position,  the  form  will  be  that  of  the  arch,  the  strength  of 
which  is  seen  in  the  stability  of  the  bridge  supported  by 
arches.     See  the  beautiful  form  of  the  Skull,  which  has  been 
demonstrated  to  be  the  most  perfect  possible. 

51.  The  bones  being  hollow  (Fig.  7),  is  an  exceedingly 
ingenious  arrangement,  as  thereby  they  may  be  large  and 


24  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

strong,  and  yet  light.  At  first  it  does  not  seem  consistent 
that  the  bones  are  as  strong,  being  hollow,  as  they  would  be 
if  solid.  But  if  a  green  twig  be  broken,  the  outer  layers  will 
be  seen  to  give  way  first,  when  the  inner  layers  immediately 
break.  Notice  also  how  heavy  a  head  of  grain  a  single  straw 
will  support,  even  when  the  wind  is  blowing  furiously,  and 
it  will  be  evident  the  hollowness  of  the  bone  is  as  it  should  be. 

Fig.  7. 


52.  The  outer  surface  of  the  bone  is  more  solid  or  dense 
than  the  part  within,  which  grows  more  and  more  spongy  - 
like  in  appearance,  though  it  is  firm  to  the  touch,  till  in  the 
centre  of  the  long  bones  a  perfect  hollow  would  be  found. 

53.  The  bones  are  also  able  to  resist  the  effect  of  blows 
and  weight,  by  the  assistance  of  the  soft  parts,  which  being 
attached  to  the  bones,  act  sometimes  as  stays,  and  being 
elastic,  at  first  yield,  but  gradually  resist,  and  at  last  very 
firmly. 

54.  All  the  bones  are  covered  by  a  very  thin  but  strong 
skin  or  membrane ;  when  dry  and  peeled  from  the  bone,  it 
appears  like  tissue  parchment.      It  is  called  the  Periosteum 
(about  bone).      Upon  particular  bones,  however,  it  is  called 
by  specific  names,  as  that  upon  the  skull  is  called  the  Peri- 
cranium (about  cranium). 

55.  Wherever  the  bones  are  hollow,  a  similar  membrane 
exists  lining  the  cavity. 

56.  Upon  the  healthy  condition  of  these  membranes  de- 
pends the  healthy  state  of  the  bony  layers  under  their  imme- 


SEC.   1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  25 

diate  influence.      Hence  disease  of  this  membrane  speedily 
produces  the  most  tedious  diseases  of  the  bone. 

57.  Two  diseases,  called  in  common  language,  "  fever- 
sore,7'*  and  "  felon,"  are  similar  affections;  one,  of  the  perioste- 
um of  the  long,  bones  ;  the  other,  of  that  of  the  shorter  bones. 

58.  "  Felon  "  is  usually  soon  detected,  but  "  fever-sore," 
which  is  much  more  serious  in  its  consequences  and  extent, 
is  usually  mistaken,  till  it  is  too  late  to  call  in  the  assistance 
of  the  skilful  surgeon  with  the  most  effect. 

59.  There  is,  however,  a  striking  difference  between  the 
pain  produced  by  this  complaint  and  rheumatism.     It  usually 
occurs  in  young  persons  who  are  not  likely  to  be  troubled 
with  rheumatism,  which  is  apt  to  manifest  itself  about  the 
joints,  and  either  affects  several   at  once,  or  wanders   from 
one  to  another.     In  fever-sore  the  pain  is  not  felt  at  the  joints, 
is  local,  continuous,  and  increasing. 

60.  The  instant  the  existence  of  the  disease  is  suspected, 
the  advice  of  experience  is  required,  as  the  disease  can  be 
readily  conquered,  only  during  a  few  days  of  its  commence- 
ment.    If  it  be  decided  that  an  operation  is  required,  such  as 
cutting  down  to  the  bone  to  cause  bleeding  from  the  inflamed 
bloodvessels  of  the  diseased  membrane,  or  perforating  the 
bone,  that  the  internal  membrane  may  be  reached,  it  will  not 
answer  to  hesitate,  for  while  indecision  is  waiting,  the  disease 
will  gain  a  firm  foothold ;  or  if  it  be  determined  that  the  con- 
tinuous application  of  cold  will  disperse  the  blood  from  the 
part  and  change  its  action,  it  is  plain  that  directions  must  be 
very  promptly  and  thoroughly  followed,  as  the  danger  is  im- 
mediate and  imminent. 

61.  If  the  bones  were  brought  directly  in  contact  with 
each  other,  their  composition  is  such,  that  the  most  unpleasant 
jars  or  concussions  would  be  produced,  even  when  walking 
in  the  gentlest  manner,  and  every  motion  would  produce 
harmful  friction. 


26  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

62.  To  prevent  such  results,  the  bones  at  the  points  of 
contact  are  covered  with  cartilage,  or  what  is  commonly 
called  gristle ;  it  also  serves  to  lengthen  out  some  of  the 
bones  (as  the  ribs,  Figs.  1,  2,  and  3) ;  to  increase  the  secu- 
rity of  the  joints  (Fig.  8)  ;  and  as  cushions  (Fig.  9),  by  the 
yielding  of  which  as  a  whole,  or  upon  one  side  or  the  other, 
the  supported  parts  are  carried  with  the  greatest  safety,  or 
bent  with  the  greatest  ease. 

Fig.  8. 


Fig.  8.— D,  Body  of  a  bone,  at  the  end  of  which  a  socket  is  found.  C,  Cartilage, 
thick  at  the  «des,  and  thin  in  the  centre.  B.  Body  of  a  bone,  at  the  end  of  which  a 
round  head  is  found.  A,  Cartilage,  thin  at  the  sides,  and  thick  in  the  centre. 

63.  Cartilage  is  admirably  adapted  to  its  purpose,  by  its 
capability  of  receiving  a  smooth  finish,  of  which  any  one 
may  satisfy  himself  by  examining  almost  any  movable  joint 
of  an  animal,  but  especially  by  its  elasticity ;    that  is,  when 
acted  upon  by  force  it  yields,  but  returns  to  its  former  posi- 
tion and  conditions  when  the  force  is  removed. 

64.  Its  elasticity  depends  upon  its  composition,  which 
varies  with  its  situation  and  use,  the  person  examined,  and 
the  period  of  life  when  the  examination  is  made. 

65.  The  general  rule  is,  that  the  cartilages  grow  thinner, 
firmer,  and  less  elastic,  with  increasing  age.     This  will  ac- 
count for  the  shortened  stature  of  old  people,  as  well  as  the 
stooping  form  ;*    for  by  Figs.  1,  2,  and  3,  it  will   be  seen 

*  Would  it  be  a  good  thing  for  the  old  man  to  be  straight,  when  the 
elastic  springs,  cushions,  or  cartilages  of  his  back  have  become  unfit  for 
the  fulfilment  of  their  duty  1  Evidently  not.  Every  jar  received  by  the 
lower  paits  of  the  body  would  be  transmitted  in  a  direct  line  to  the  head 
and  nervous  system  ;  and  such  continually  repeated  concussions,  though 
slight  as  possible,  would  shortly  destroy  life. 


1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  27 

Fig.  9. 


Fig.  9. — Back  bone,  spinal  column,  vertebral  column.  6,  c,  d,  Bodies  of  verte- 
brae ;  the  projections  on  the  opposite  side  are  called  spinous  processes ;  above  b  they 
incline  down  but  little ;  between  b  and  c  they  incline  very  much ;  between  c  and  a, 
but  little,  if  any.  Spaces  between  vertebrae  are  filled,  in  life,  with  the  cushion-like 
cartilages.  Above  6,  are  the  cervical  (neck)  vertebra ;  6  to  c,  dorsal  (back)  or  cheat 
vertebrae  ;  c  to  d,  lumbar  (loins)  vertebrae ;  d,  e,  sacrum ;  e,f,  coxcyges. 


28  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

that  the  cushions  of  the  back,  if  diminished  in  thickness,  will 
allow  the  head  and  entire  trunk  to  fall  forward. 

66.  But  with  the  head  leaning  forward,  works  on  Natural 
Philosophy  (see  "Composition  of  Forces")  will  show,  and  ex- 
perience proves,  the  danger  is  avoided.    I  would  here  observe 
how,  upon  examination,  all  things  are  found  to  be  most  ad- 
mirably adapted  to  our  good,  when  at  first  glance  there  would 
seem  to  be  something  to  correct.      There  is  a  rich  treat  and 
great  practical  source  of  knowledge  to  the  man  who  will  ask 
the  why  and  wherefore  of  what  he  sees* 

67.  In  some  instances  the  cartilages  become  bony,  or 
technically,  "  ossified,"  in  advanced  life. 

68.  To  retain  the  bones  and  cartilages  in  their  places  at 
the  movable  joints,  something  of  great  strength,  yet  possessing 
a  certain  degree  of  flexibility,  is  required,  to  stretch  across 
from  one  part  to  another  and  be  firmly  united  to  each.     Such 
is  the  nature  of  the  ligaments. 

69.  They  are  the  pearl-colored,  lustrous,  strong  parts, 
found  about  the  joints  of  any  animal.     They  are  in  the  form 
of  straps  (Fig.  10);    in  the  form  of  bands  completely  sur- 
rounding (Fig.  11);    or  in  the  form  of  cords.      They  are 
sometimes  found  within  the  joint,  but  usually  without,  stretch. 
ing  between,  growing  to,  and  binding  together  the  different 
parts,  allowing  motion  in  required  directions  and  preventing 
it  in  others.* 

*  It  does  not  seem  judicious  to  speak  of  any  course  which  should  be 
pursued,  till  its  propriety  has  been  proved.  But  sprains,  strains,  or 
wrenches  of  the  ligamentous  parts  are  so  common,  a  word  in  respect  to 
them  will  be  expected  here.  They  will  be  again  spoken  of  in  an  ad- 
vanced part  of  the  work,  when  the  why  and  wherefore  will  be  clearly 
given ;  as  it  is  easily  shown,  that  lotions,  plasters,  and  all  this  class  of 
things  so  commonly  used,  are  of  little  worth,  and  cause  fruitless  expen- 
ditures of  trouble,  time,  and  money  ;  while  time,  patience,  the  applica- 
tion of  heat  or  cold,  with  rubbing,  are  chiefly  to  be  depended  upon.  If 
there  be  heat  or  redness  of  a  sprained  part,  and  almost  always  if  there 
be  pain,  the  part  must  be  kept  perfectly  quiet,  rubbing  avoided,  and  cold 
applied  till  relief  is  felt  and  the  heat  subsides.  Sometimes  persons  have, 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  29 

Fig.  10. 


Fig.  10.— Represents  the  strip-like  ligaments  which  pass  across  from  one  bone  to 
another  in  the  hand,  and  also  the  inter-osseoua  (between-bone)  ligament  which  connects 
the  bones  of  the  lower  arm. 

70.  Atmospheric  pressure  is  also  thought  to  exert  a  pow- 
erful influence  in  retaining  the  bones.  I  have  seen  a  state- 
ment that  forty  pounds  weight  was  required  to  draw  the  thigh 

under  such  circumstances,  pumped  cold  water  upon  a  sprained  ankle, 
and  learned  from  experience  the  benefit.  If  the  part  be  cold  and  inac- 
tive, brisk  rubbing  and  the  application  of  heat  will  be  advisable  ;  and 
application  of  substances  irritating  to  the  skin  may  be  made,  if  desirable. 
The  part  may  be  wrapped  in  flannel  or  a  cloth  dipped  in  warm  water, 
and  covered  with  oiled  silk  ;  but  the  chief  dependence  must  be  placed, 
in  all  cases,  on  time,  patience,  and  rest.  If  the  part  be  used  from  time 
to  time,  it  will  be  a  long  while,  perhaps  years,  in  recovering.  By  long 
disuse  a  part  is  apt  to  be  stiff,  when  in  fact  it  is  well ;  it  should  then  be 
rubbed  often  and  thoroughly,  it  being  certain  that  no  inflammation  exists, 
which  will  be  manifested  by  pain  and  soreness ;  and  forced  motion  be 
produced,  slight  at  first,  but  increased  from  day  to  day  till  perfect  action 
of  the  part  is  obtained.  The  restoration  of  sprained  parts  is  so  slow, 
there  is  great  difficulty  in  persuading  a  person  to  wait  and  avoid  exercise. 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  11. 


Pig.  11.— The  hip  joint  opened.  C  L,  Capsular  ligament,  which,  like  a  band,  passes 
round  the  joint,  attached  on  one  side  to  the  hip,  and  on  the  other  to  the  thigh  bone. 
R  L,  Round  ligament  passing  from  nearly  the  centre  of  the  round  head  of  the  thigh 
cone  to  nearly  the  centre  of  the  deep  socket. 

bone  from  its  socket,  after  all  its  connections  had  been  sever- 
ed, indeed,  after  it  had  been  entirely  removed  and  was  re- 
placed. We  see  this  principle  so  simply  and  successfully 
used  by  the  dentist  and  others,  that  there  will  be  no  objection 
to  allowing  its  application  in  case  of  the  joints. 

71.  The  fleshy  parts  clothing  the  bones  serve  also  to  re- 
tain the  bones  when  in  place,  but  exert  an  equally  powerful 
influence  to  prevent  their  return  when  dislocated. 

72.  Notwithstanding  the  admirable  structure  of  the  car- 
tilage, the  almost  constant,  slight  or  extensive  motion  at  the 
joints  would  produce  serious  friction. 

73.  To  prevent  this  as  far  as  possible,  the  movable  joints 
are  lined  with  a  membrane  or  skin  called  "  synovial  mem- 
brane."    It  is  attached  by  one  side  to  the  cartilage  (Figs.  12 
and  13),  the  other  being  "  free,"  that  is,  not  attached  to  any 
thing. 

74.  In  this  membrane  an  exceedingly  glairy  fluid,  well 
adapted  to  its  purposes,  called  "  synovial  fluid,"  is  found.     It 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  31 

Fig.  12. 


Fig.  12.— C  L,  Capsular  ligament.  R  L,  Round  ligament.  F,  Thigh  or  femor  bone. 
B  H,  The  same  sawn  open,  exhibiting  the  marrow-filled  cells  composing  the  internal 
parts  of  many  bones,  as  at  P  P  also.  P  P  P,  Hip  bone.  S  S,  Space  rilled  with  svno- 
vial  fluid,  but  here  represented  as  much  greater  than  in  reality,  the  surfaces  of  the 
eynovial  membrane  in  fact  being  closely  in  contact. 

exudes  from  the  free  surface  as  the  minute  drops  of  perspi- 
ration, when  scarcely  perceptible,  on  the  face. 

75.  But  the  fluid  would  accumulate,  or  remaining,  would 
be  liable  to  the  same  fault  as  even  the  most  delicate  oils  which 
human  art  has  obtained :  viz.,  would  thicken,  and  render  a 
"  cleaning"  of  the  joints  necessary,  were  it  not  for  another 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  13. 


Fig.  13. — Knee  joint.  1,  Lower  end  of  thigh  bone.  5,  Upper  end  of  "  shin  "  bone. 
3,  Knee-pan.  2,  Tendon  of  muscles  acting  on  knee-pan,  or  patella  or  rotulla.  4,  Liga- 
rnent  connecting  patella  to  "  shin-bone,"  or  tibia.  Stars  show  the  synovial  membrane. 
6,  A  buraa,  or  pouch  or  purse. 

duty  the  synovial  membrane  performs.  It  continually  takes 
up  and  removes  the  fluid  which  a  short  time  before  was  de- 
posited.* 

76.  The  bones  of  the  skeleton  are  240  in  number,  not 
counting  several  small  bones,  which  are  considered  as  acci- 
dental and  not  necessary  to  the  framewcrk. 

77.  Most  of  these  are  united,  so  as  to  form  movable  joints, 
some  so  as  to  form  immovable  joints. 

78.  The  eight  bones  of  the  skull  (Fig.  14)  are  of  this  last 


*  Though  only  a  drop  of  fluid,  perhaps  not  as  much,  would  be  found  in 
a  healthy  joint  at  any  one  time,  one  author  has  computed  that  not  less 
than  five  quarts  of  synovial  fluid  is  required  in  24  hours  by.  the  joints  of  a 
laboring  man. 

In  this,  as  in  many  other  cases,  it  is  evident  that  one  part  performs 
more  than  one  duty,  though  the  contrary  is  frequently  asserted  ;  it  is  also 
evident  that  the  same  symptoms  may  be  exhibited  by  different  causes  ; 
for  an  accumulation  of  fluid  in  the  joints  may  take  place,  either  because 
it  is  formed  too  rapidly,  or  not  removed  as  it  should  be.  How  absurd 
then  the  idea  that  one  medicine  shall  cure  all  diseases  having  the  same 
symptoms — and  how  much  more  absurd  that  any  medicine  or  course  of 
treatment  shall  cure  all  diseases.  It  must  be  evident,  if  disease  exist,  the 
cause  must  be  looked  for ;  if  this  be  done  in  season,  and  the  cause  pre- 
vented from  further  action,  rarely  will  any  thing  else  be  required.  But  it 
will  be  perfect  nonsense  to  attempt  to  remove  disease  while  its  causes  are 
still  existing  to  reproduce  it. 


SEC.  l.j  BONES,  CARTILAGES,  AND  LIGAMENTS.  33 

Fig.  14. 


Fig.  14.— The  bones  of  the  skull  separated.  1,  Frontal,  only  half  seen.  2,  Parietal 
(wall).  3,  Occipital  (back),  only  half  is  seen.  4,  Temporal.  5,  Nasal  (nose).  6,  Ma- 
lar  (cheek).  7,  Superior  (upper)  maxillary  (jaw).  8,  Unguis  (nail  form,  being  about 
the  size  and  thickness  of  tne  fingernail).  9,  Inferior  (lower)  maxillary  (jaw).  Be- 
tween 4  and  6,  a  part  of  the  spenoid  or  wedge-shaped  bone  is  seen.  Another  bone 
assisting  to  form  the  skull,  but  not  here  seen,  is  called  the  ethmoid  (sieve-like,  from 
being  full  o '  holes)  and  situated  between  the  sockets  of  the  eyes,  and  forms  the  roof 
of  the  nose  2,  4,  5,  6,  7,  8,  are  double.  The  small  bone,  and  others  like  it,  seen  in  a 
line  between  3  and  1,  are  called  ossa  triquetra. 

79.  Each  of  the  eight  is  composed  of  three  layers  differing 
from  each  other  in  their  structure. 

80.  The  outer  layer  is  quite  tough,  and  called  the  fibrous 
or  external  table  of  the  skull ;  its  edges  are  notched  very 
irregularly  to  appearance,  but  so  that  each  bone  of  the  skull 
perfectly  corresponds  with  its  neighbor,  into  which  it  is  lock- 
ed, or  dovetailed,  as  the  expression  is ;    hence  it  must  be 
formed  upon  some  uniform  and  general  principle. 

2* 


34  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

81.  The  joints  formed  between  the  external  tables  are 
called  sutures  or  seams ;  these  are  also  called  by  specific 
names,  as  the  sagittal  suture,  coronal  suture,  squamous  su- 
ture, &c. 

82.  Small  bones,  called  ossa  triquetra,  are  also  seen  in 
Fig.  14,  which  may  or  may  not  be  present :    their  utility  is 
not  appreciated 

83.  The  middle  layer  or  table  is  cancellated  or  spongy, 
and  lessens  the  jarring  effect  of  blows  upon  the  skull. 

84.  The  internal  table  is  called  vitreous  or  glassy,  as  it 
is  very  brittle.     If  its  edges  were  like  those  of  the  external 
table,  a  slight  blow  upon  the  head  would  break  off  the  points ; 
hence  its  edges  are  square,  and  an  even-looking  joint  is  the 
result. 

85.  In  advanced  age  the  sutures  are  sometimes  closed  up 
by  the  bones  uniting  together  firmly.     In  early  life,  on  the 
other  hand,  the  firm  bone  has  not  covered  the  whole  brain, 
but  "  soft  spots"  exist :  the  one  on  the  top  of  the  head,  called 
a  fontanelle,  being  an  example,  where,  by  pressure,  the  head 
may  be  lessened  in  size,  and  other  benefits  obtained. 

86.  The  bones  of  the  face,  fourteen  in  number,  are  im- 
movably united,  except  the  lower  jaw ;    its  joint  allows  of 
motion  downward,  upward,  forward,    backward,   and  from 
side  to  side. 

87.  The  socket  in  which  the  lower  jaw  moves  is  so  shal- 
low, that  sometimes  a  person,   by  opening  the  mouth  wide 
while  gaping  or  the  like,  throws  the  jaw  from  its  place,  and 
cannot  have  his  "  gape  out,"  till  something  be  done. 

88.  To  replace  the  jaw,  let  the  thumbs  of  a  person  be 
placed  against  the~lower  back  teeth,  and  the  fingers  under  the 
chin ;  press  downward  and  backward  with  the  thumbs,  and  try 
at  the  same  time  to  raise  the  jaw  with  the  fingers.     From  the 
frequent  and   powerful  motions  of  the  jaw,  its  joint  is  sub- 
jected to  unusual  friction.     To  diminish  this  the  joint  is  sup- 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  35 

plied  with  an  extra  cartilage,  and  with  two  synovial  mem- 
branes.  By  means  of  these  the  same  end  is  obtained  as  the 
machinist  gains  by  friction  wheels  (Fig.  15).* 

Fig.  15. 


Fig.  15.— Section  of  the  joint  of  the  lower  jaw.  3.  Cartilage  dividing  the  joint  Into 
two  parts.  4,  The  upper,  5,  the  lower  cavity,  both  lined  with  synovial  membrane. 
1,  The  socket  in  the  bone  which  receives  the  upper  surface  of  the  cartilage.  7,  A  por- 
tion of  the  lower  jaw,  which  moves  upon  the  under  surface  of  the  cartilage.  6,  Th« 
cartilage  taken  out  of  the  joint 

89.  Composing  the  back-bone  are  found  24  vertebrae, 
placed  one  above  the  other,  the  lower  one  resting  on  the  sa- 
crum, which  is  terminated  by  the  coccyx  (Fig.  9). 

90.  Between  the  upper  or  first  bone  and  the  head,  what 
is  called  a  hinge-joint  is  found,  which  allows  the  nodding  mo- 
tion of  the  head,  and  with  great  rapidity,  if  desirable. 

91.  The  first  and  second  bones  are  united  in  a  very  cu- 
rious manner.     From  the  second  bone  a  prominence,  called 
a  tooth  or  pivot,  rises  up  through  the  first,  and  is  attached  to 
the  skull   by  a  ligament  passing  between  them.     Another 
ligament  passes  from  side  to  side  of  the  first,  behind  the  tooth, 
which  has  a  kind  of  neck  at  the  point,  where  this  ligament 
acts  against  it.     Thus  every  thing  is  held  firmly  in  its  place, 
and  yet  the  most  desirable  rotary  motion  of  the  head  with  great 
quickness  is  allowed. 

*  The  bones  of  the  ears,  the  teeth,  and  the  TJ-like  or  hyoid  bone  wiH 
be  described  hereafter. 


86  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

92.  Motion  of  the  other  bones  of  the  back  is  obtained  by 
cartilages  situated  between  the  "  bodies"  or  front  parts  of  the 
"  vertebrae  "(Fig.  9).      These  are  much  thicker  between  the 
lower  than  between  the  upper  bones  of  the  back ;  they  are  also 
much  more  firm  at  the  outer  surface  than  within,  where  the 
substance  more  resembles  jelly.     In  some  animals,  indeed, 
the  centre  is  found  occupied  by  a  bag  or  bladder  of  quite 
fluid  substance,  by  means  of  which  still  greater  suppleness  is 
obtained. 

93.  As  the  bones  are  drawn  towards  each  other,  this  sub- 
stance pressed  upon,  yields,  becoming  thinner  at  that  point 
and  thicker  at  the  opposite  side.     Thus,  by  acting  upon  the 
bones  in  the  proper  way,   any  desired  motion  is  obtained. 
But  joints  of  this  kind  do  not  allow  of  the  greatest  rapidity 
of  motion,  even  to  the  frequently  exercised  back ;  hence  a 
different  arrangement  is  found  in  case  of  the  two  upper  bones, 
by  means  of  which  the  desirable  rapid  motions  of  the  head 
are  gained  to  perfection. 

94.  To  the  "  back-bone"  the  ribs  are  attached,   forming 
hinge  joints,  by  means  of  which  they  can  be  moved  upward 
and   downward.      By  their  form  and  composition  they  are 
remarkably  elastic  for  bone ;  they  pass  around  to  form  the 
sides  of  the  chest,  and  are  lengthened  out  by  means  of  car- 
tilage, which  is  very  elastic  in  early  years,  but  firmer  in 
advanced  life,  and  sometimes,  in  old  age,  changed  into  per- 
fect bone.     From  the  upper  seven,  which  are  called  the  true 
ribs,  the  cartilage  becomes  attached  to  the  "  breast  bone.1' 
From  the  three  or  four  next,  the  cartilage  passes  up  and  be- 
comes part  of  that  from  the  rib  above ;  while  the  lower  one 
or  two  ribs  are   merely  tipped  with  cartilage,  and  called 
floating  ribs. 

95.  Such  a  framework  as  the  chest  was  required  to  give 
support  to  the  arms,  and  was  also  needed  to  protect  the  lungs 
and  heart ;  hence  the  ribs  are  used  to  fulfil  both  purposes ;  at 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  37 

the  same  time  it  was  necessary  also  that  the  ribs  should  not 
be  immovably  attached  to  the  back-bone,  or  how  could  a 
person  bend  the  back  1  Motion  of  the  ribs  was  also  neces- 
sary in  the  process  of  breathing ;  hence  we  see  that  not  only 
one  end,  but  several,  are  gained  by  the  same  beautiful  and 
simple  means. 

96.  The  shoulder-blades  are  suspended,  as  it  were,  by 
the  fleshy  parts,  to  the  ribs  and  back-bones,  and  they  lie  upon 
the  ribs,  though  not  directly,  as  the  flesh  beneath  prevents 
them  from  coming  in  contact  with  the  ribs.     It  is  important 
that  the  arms  of  man  hang  by  his  side ;  in  the  cow,  or  horse, 
or  dog,  &c.,  it  is  important  that  they  be,  as  it  were,  in  front. 
In  man,  therefore,  the  shoulder-blades  are  prevented    from 
falling  upon  the  chest  at  the  sides,  by  the  collar-bones,  which 
are  wanting  (except  mere  rudiments)  in  the  animals  above- 
mentioned. 

97.  At  one  extremity  the  collar-bones  are  connected  to 
the  breast-bone  ;  at  the  other  to  the  shoulder  blades  (y,  Fig.  1), 
forming  joints  which  allow  of  limited  but  sufficient  motion. 

98.  Placed  in  this  manner  the  shoulder-blades  can  move 
upward,  downward,  backward,  forward,  or  in  a  rotary  man- 
ner, with  the  greatest  freedom,  and  without  particularly  af- 
fecting the  ribs,  while  their  position  in  relation  to  the  ribs  is 
such,  that  all  deformities  of  the  chest,  at  the  back  part,  wheth. 
er  of  the  back-bone  or  ribs,  will  be  exhibited  by  the  shoulder- 
blades. 

99.  At  the  shoulder,  the  upper  arm  bone  (&,  Fig.  1)  is 
connected  with  the  scapula  or  shoulder-blade  in  such  a  man- 
ner as  to  form  what  is  called  a  ball  and  socket  joint. 

100.  By  this  means  and  the  mobility  of  the  shoulder- 
blades,  the  greatest  latitude  of  motion  is  allowed  to  the  arm 
and  hand.    That  this  may  be  increased  to  the  utmost  possible 
degree,  the  socket  has  been  made  exceedingly  shallow.    Were 
it  not  for  the  cartilage  that  deepens  it,  it  could  hardly  be 


38  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

termed  a  socket.      On  this  account  the  bones  at.  the  shoulder 
are  more  easily  dislocated  than  any  others. 

101.  A  hinge  joint  is  found  at  the  elbow,  by  which  the 
hand  can  be  raised  up  and  thrown  down  ;  but  lateral  motion 
is  prevented  both  by  the  form  of  the  bones  and  the  arrange- 
ment of  the  ligaments.     At  the  lower  and  back  part  of  the 
upper  arm  bone  or  humerus,  a  cavity  is  found,  into  which 
the  hook-like  prominence  felt  at  the  elbow  shuts,  when  the 
hand  is  thrown  down.     It  is  so  arranged  that  the  bones  of  the 
lower  arm  will  never  be  in  precisely  the  same  plane  with 
the  upper  bone. 

102.  Another  but  smaller  cavity,  opposite  to   the  first 
mentioned,   will  be  found  at  the  front  and  lower  part  of 
the  humerus.     A  correspondingly  small  point  of  one  of  the 
bones  in  the  lower  arm  shuts  into  it,  preventing  the  bones  of 
the  lower  arm  from  being  brought  parallel  with  the  humerus, 
whereby  great  safety  of  the  joint  is  insured. 

103.  No  arrangement  in  the  body  is  more  ingenious  than 
the  combination  of  the  two  bones  in  the  lower  arm,  by  means 
of  which  we  turn  a  gimlet,  a  key,  and  perform  all  such  use- 
ful motions.    Here  are  two  bones,  the  "ulna"  (e,  Fig.  1)  and 
"radius"  (d,  Fig.  1).     The  upper  end  of  one,  with  the  hu- 
merus, forms  the  elbow  joint ;    the  lower  end  of  the  other, 
with  the  wrist  bones,  forms  the  wrist  joint,  and  vice  versa — the 
upper  end  of  the  radius  forms  no  part  of  the  elbow,  neither 
does  the  lower  part  of  the  ulna  assist  in  forming  the  wrist 
joint. 

104.  The  rounded  upper  end  of  the  radius,  which  is  the 
bone  back  of  the  thumb,  turns  in  a  slight  cavity  in  the  upper 
part  of  the  ulna,  its  fellow,  and  is  fastened  there  in  such  a 
manner  as  to  forbid  release,  but  yet  allow  of  a  turning  mo- 
tion.    Between  the  bones  (Fig.  10),  for  their  entire  length,  a 
ligament  is  found,  strong  but  very  complying,  and  at  the  lower 
extremity  of  the  radius,  the  hand  is  attached  ;    when,  there- 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  39 

fore,  the  radius  is  rolled  over  the  ulna,  which  remains  quiet, 
the  hand  is  made  prone  or  supine  (palm  downward  or  upward). 

105.  The  wrist  joint  is  a  compound  hinge  joint,  permitting 
motion  of  the  hand  up  and  down,  as  well  as  from  side  to  side. 

106.  The  wrist  is  composed  of  eight   bones,  small,  but 
united  in  a  manner  so  exceedingly  strong,  that  the  hand  must 
be  crushed  before  they  can  be  displaced. 

107.  To  the  wrist  are  connected  the  several  bones  which 
form  the  frame  of  the  hand ;    to  these  again  the  bones  of  the 
fingers,  the  arrangement  of  which  is  so  simple  and  evident, 
that  a  child  may  study  them  without  a  tutor. 

108.  To  the  lower  part  of  the  sacrum  (Fig.  9)  the  coc- 
cyx is  attached.     This  is  composed  of  several  bones,  early  in 
life ;    at  a  later  period  they  become  consolidated  with  each 
other  and, also  with  the  sacrum. 

109.  To  the  sides  of  the  sacrum  (w,  Fig.  1)  are  attached 
the  hip  bones  (s  s,  Fig.  1),  bound  in  their  places  very  strong- 
ly by  ligaments.      They  are  very  irregular  in  form,  and 
unite  with  each  other  in  the  front  central  line  of  the  body 
by  a  joint  called  "  symphysis  pubis."    It  is  of  the  kind  which 
does  not  allow  of  motion  or  separation  of  the  bones,  except 
with  the  severest  effort. 

110.  In  the  outer  sides  of  these  bones,  looking  somewhat 
downward,  deep  sockets  are  excavated,  in  which  are  placed 
the  heads  of  the  thigh  bones.     These  heads  will  be  observed 
not  on  the  end  of  the  shaft,  but  connected  with  it  (Fig.  16) 
by  the  neck. 

111.  "Hip  disease"  may  profitably  be  noticed,   as  its 
worst  results  may  often  be  attributed  to  ignorance  of  its  early 
symptoms  or  injudicious  neglect.     One  of  its  first  symptoms 
is,  pain  at  the  knee,  with  no  apparent  cause.     Secondly,  the 
child  will  stand  mostly  on  the  sound  leg.     Thirdly,  if  pres- 
sure be  made  upon  the  hip  joint  and  the  leg  rolled  around, 
j>ain  will  be  felt  in  the  hip,  if  disease  exist.     The  advice  of  a 


40 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  16. 


Fig.  16.— H,  Head,  or  ball.    N,  Neck.    P,  Prominence.     T  b,  Body  of  thigh  bone. 
S,  Socket.    H  6,  Hip  bone. 

skilful  surgeon  must  then  be  very  strictly  followed,  and  it  is 
advisable  to  read  some  good  treatise  (Liston  or  Cooper)  on 
surgery,  that  speaks  of  the  disease  in  particular,  as  almost 
every  thing  depends  upon  good  nursing  for  a  long  time,  of 
which  the  patient  must  be  persuaded,  or  he  will  perhaps  be 
seduced  by  the  promises  of  unprincipled  quacks,  whose  cha- 
racter he  learns  too  late. 

112.  The  twisted  form  of  the  thigh  bone  or  "femur" 
(z,  Fig.  1 ),  is  remarkable ;  being  uniformly  so,  it  doubtless 
serves  some  important  purpose.  At  its  lower  extremity 
(7,  Fig.  1)  it  is  much  enlarged,  and  forms,  with  the  enlarg- 
ed upper  extremity  of  the  "tibia"  or  shin  bone  (m,  Fig.  1), 
the  knee  joint,  by  which  the  foot  and  lower  leg  is  flexed 


SEC.   1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  41 

backward  to  the  greatest  degree,  and  brought  again  into  a 
perpendicular  below  the  femur,  its  further  motion  forward 
being  prevented  by  ligaments.  At  first  view  this  would  seem 
to  be  one  of  the  weakest  joints,  but  the  motions  required  of 
it  are  so  simple  that  it  can  be,  and  is,  made  exceedingly 
strong  by  ligaments.  Subject  to  great  and  almost  constant 
pressure,  it  has  been  furnished  with  extra  cartilages  (Fig. 
13),  which  placed  between  the  bones  and  covered  on  both 
sides  with  synovial  membrane,  render  it  quite  perfect. 

113.  In  front  of  and  sliding  over  this  joint,  is  found  the 
"knee-pan,"  to  be  hereafter  spoken  of. 

114.  In  the  lower  part  of  the  leg  are  two  bones,  stronger 
and  presenting  more  surface  than  if  but  one,  especially  as  there 
is  a  ligament  stretching  between  them  for  their  entire  length. 
They  also  serve  as  supports  to  each,  if  either  be  broken. 

115.  At  their  lower  extremities  is  found  the  ankle  joint, 
a  part  exceedingly  subject  to  be  sprained,  as  it  was  necessary 
to  produce  by  it  a  double  motion,  up  and  down,  and  from  side 
to  side.     It  could  not,  therefore,  be  endowed  with  the  strength" 
of  the  knee.      The  force  which  is  exerted  when  the  weight 
and  entire  lever  power  of  the  body  is  brought  to  bear  on  the 
ankle,  placed  in  an  improper  position,  is  but  little  appreciated. 
With  a  sprained  ankle,  therefore,  the  greatest  care  must  be  tak. 
en ;  for  a  slight  misstep  will  undo  the  curative  process  of  weeks. 

116.  The  ankle  bones,  seven  in  number,  resemble  the 
wrist  bones  in  the  strength  of  the  bands  which  confine  them 
together.     With  the  bones  stretching  forward  to  the  toes,  they 
form  an  arch  (Fig.  17),  which  should  not  be  depressed  by 
setting  the  child  upon  its  feet  prematurely ;  nor  should  a  de- 
formity of  the  feet  be  produced  by  shoes  which  cramp.   How- 
ever  genteel  a  slender  foot  may  look,  an  attempt  to  produce 
it,  by  wearing  tight   shoes,   will   not  only  cause  great  dis- 
comfort, but  also  a  very  ungraceful,  gait,  and  prove  a  great 
discount  to  personal  appearance  in  several  respects. 


42  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  1. 

Fig.  17 


Fig.  17.— Section  of  the  bones  and  ligaments  of  the  foot  and  ankle.  The  figures 
refer  to  the  bones,  and  the  letters  to  the  ligaments,  except  0,  which  is  the  "heel  cord," 
a  tendon  of  certain  muscles. 

117.  The  joints  of  the  toes  appear  to  be  of  very  limited 
use ;  but  upon  further  observation,  they  will  be  found  to  es- 
sentially aid  in  walking  with  ease,  and  if  used  as  in  case 
of  some  born  without  hands,   become  almost  as  perfect  as 
the  finger  joints. 

118.  Considered   as  a  whole,  nothing   could  be  better 
adapted  to  its  purposes  than  the  foot,  when  perfect ;  when 
imperfect,  it  is  usually  the  fault  of  man.     It  was  designed  to 
be  used  with  ease  in   walking,  and  to  disperse  the  force 
which  acts  upon  it  when  striking  the  ground. 

119.  Composed  of  twenty-six  bones,  more  or  less  cellular 
internally,  united  by  cartilaginous  joints,  so  as  to  form  an 
elastic  arch,  a  step  must  be  very  unfortunate  the  force  of 
which  is  allowed  to  act  in  a  great  degree  even  upon  the  knee. 
Yet  by  ligaments  how  strong  the  foot  is  made !     A  loaded 
cart  has  passed  over  it  and  caused  but  a  severe  bruise. 

120.  The  perfection  of  all  the  bones  in  preventing  the 
transmission  of  concussion,  or  the  effect  of  blows,  will  be  seen 
by  placing  several  solid  ivory  balls  in  contact  with  each  other 
and  striking  one  with  force — the  last  will  fly  off  correspond- 
ingly ;  but  interplace  a  bone  of  the  foot,  and  the  movement 
of  the  last  ball  will  be  but  slight,  on  account  of  the  spongy 
nature  of  the  inside  of  the  bone. 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  43 

121.  When  the  foot  strikes  the  ground,  the  joints  of  the 
body  are  more  or  less  flexed,  and  the  force  which  acts  upon  the 
lower  parts  of  the  body  is  more  and  more  dispersed  in  the  direc- 
tion of  the  dotted  lines,  Fig.  3.  This,  together  with  the  nature 
of  the  cartilages  furnished  to  the  joints,  especially  the  cushions 
of  the  spinal  column,  gives  to  the  delicate  and  easily  injured 
brain  the  most  perfect  security. 

Fig.  3,  B. 


Fig.  3,  B. — Represents  the  outline  oi  Fig.  3.  The  dotted  lines  represent  how  the 
foot,  when  walking,  is  put  upon  the  ground.  The  force  acting  on  the  heel,  at  a}  ia 
scattered,  viz :  a  part  of  the  force  acts  through  the  ankle  and  is  lost  in  the  direction 
a  6,  only  a  part  of  the  force  acting  in  the  direction  of  the  line  a  c ;  of  this,  only  a  small 
part  will  act  in  the  line  cf-  and  of  this,  only  a  part  will  act  in  the  direction  e  h ;  of 
this,  only  a  part  in  the  direction  g  k ;  and  of  this,  only  a  part  in  the  line  t  /.  In  fact, 
these  lines  represent  but  a  email  part  of  the  directions  in  which  the  force  is  scattered ; 
for  by  the  curve  of  the  thigh  bone,  its  neck  and  the  connection  of  the  hip  bones  with 
the  back  bone,  as  well  as  the  continued  curvature  of  this,  the  head  is  saved  from  the 
Budden  jar  produced  when  the  body  is  as  erect  as  it  can  be ;  for  instancy  when  a  mis- 
Btep  ia  made,  or  a  person  falling  strikes  upon  his  feet. 


44  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

122.  While  the  beautiful  structure  and  admirable  adjust- 
ment of  the  various  parts  of  this  framework  excites  in  the 
mind  the  strongest  feelings  of  pleasure,  still  greater  satisfac- 
tion will  be  felt  if  we  turn  our  attention  to  the  wonderful  ope- 
rations which  from  birth  till  death  preserve  the  perfection 
of  this  piece  of  mechanism. 

123.  First,  the  attention  is  arrested  by  the  increase  of 
size  which  is  constantly  taking  place  till  the  period  of  matu- 
rity, with  the  most  exact  regard  to  just  proportions  and  the 
uses  to  be  fulfilled. 

124.  This  enlargement  is  accomplished  by  the  gradual 
removal  of  every  part,  and  the  deposition  of  new  substance 
in  place  thereof.     (The  teeth  of  the  human  species  are  an 
exception ;  they  will  be  spoken  of  hereafter.) 

125.  The    new   deposition  takes  place   within  certain 
bounds,  in  accordance  with  the  requirements  of  the  parts ; 
hence,  if  a  boy  be  put  to  work  early  in  life,  the  bones  will 
become  consolidated  earlier  ;  if  worked  too  hard,  deformities 
of  the  bones  will  be  produced,  that  they  may  fulfil  what  is 
required  of  them,  at  an  unnatural  period  of  life. 

126.  Second;  all  through  life  even  the  hardest  parts  of  the 
system  are  wearing  out :  in  youth,  in  mature  years,  in  old 
age  even,  it  is  so.     The  worn-out  parts  are  continually  re- 
moved and  new  parts  laid  down  instead.     In  youth  this  pro- 
cess is  most  active,  in  middle  age  sufficiently  so,  in  old  age 
it  takes  place  slowly.     In  early  years,  therefore,  an  injury 
is  easily  recovered  from,  in  old  age  its  cure  is  tedious. 

127.  The  body,  therefore,  does  not  die,  nor  is  it  born  once 
only  ;    but,  with  the  exception  of  some  of  its  parts,  is  con- 
tinually dying  and  being  born,  even  in  youth. 

128.  Of  what  consequence  then,  is  this  identical  frame- 
work, which  a  few  years  ago  we  had  not,  and  a  few  years 
hence  we  shall  not  have  ?     Like  the  garments  that  cover  us, 
"  thread  after  thread  it  is  worn  away,"  but  not  like  those  does 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  45 

any  part  become  threadbare,  for  its  perfection  is  restored  con- 
tinually by  the  deposit  of  renewing  substance.  The  mind, 
then,  is  the  man. 

129.  Third ;   when  the  bones  are  broken,  a  remarkably 
active  condition  takes  place  as  a  usual  thing.     The  limb  be- 
comes exceedingly  painful,  so  that  a  person  may  not  move  the 
broken  part.    Sometimes  this  does  not  occur,  when  the  motions 
of  the  limb,  which  the  patient  will  allow,  prevent  the  parts 
from  uniting,  and  cause  them  to  be  displaced.   Under  such  cir- 
cumstances it  is  usual  for  the  surgeon  to  adopt  such  a  course 
as  shall  produce  the  desired  action  and  excite  pain. 

130.  As  genuine  bone  forms  very  slowly,  an  amount  of 
cartilage  is  first  formed  about  and  within  the  bone,  which 
supports  the  broken  bones  in  their  places,  and  allows  the  pro- 
cess of  "  knitting"  to  go  on  between  the  bones.     After  this  is 
accomplished,  the  cartilage  will  be  gradually  removed  and 
the  bone  left  as  before. 

131.  As,  when  a  limb  is  broken,  a  person's  health  is  not 
affected  in  other  respects,  he  does  not  always  appreciate  the 
importance   of  observing  the  surgeon's  advice,  which  seems 
unnecessarily  strict.     The  splints  are  to  be  thrown  aside,  he 
thinks,  when  he  can  raise  the  limb  without  bending  it  or 
feeling  pain. 

132.  If  a  limb  be  broken,  and  no  surgical  assistance  is  at 
hand,  the  limb  is  to  be  placed  as  nearly  in  a  natural  position 
as  it  can  be,  and  slips  of  thin  wood  or  the  like,  applied  as 
ingenuity   shall  suggest,   bound  on,   not  very  tightly,   but 
so  as  to  give  general  support,  and  padded,  to  obtain  the 
purpose  better.     Trust  chiefly  to  the  painfulness  of  the  part 
to  keep  the  limb  quiet,  for  bandages  which  would  do  this, 
would  be  likely  to  stop  the  circulation  of  blood.      It  will  be 
best  to  wear  the  splints  longer  than  necessary,  rather  than 
go  upon  the  other  extreme,  as  people  usually  do.     Remem- 


46 


ORGANS  OF  VOLUNTARY  MOTION. 


[CHAP.  i. 


ber,  that  a  part  is  not  cured  because  it  is  desirable,  neither 
will  opinion  alter  the  state  of  the  bone. 

133.  With  this  view  of  the  framework,  the  reader  will 
appreciate  the  effect  upon  it  of  female  dress,  .as  usually  worn, 
and  of  male  attire,  as  sometimes  worn.     While  yet  an  infant, 
the  belt  of  the  girl  is  pinned  snugly,  for  the  purpose  of  pro- 
ducing a  "  trim  figure."      Too  often  this  is  the  case,  even 
with  the  boy. 

134.  The  ribs  are  not  yet  firmly  fixed  in  their  sockets, 
are  easily  bent,  while  the  slightest  pressure  is  sufficient  to 
produce  deformity  of  the  pliable  cartilages,  which  form  the 
front    part   of   the    chest.      There   is   no   doubt,   that   the 
usual  custom  will  lessen  the  size  of  the  waist.     But  is  this 
an  improvement  ?     (Figs.  18,  19.)     If  the  reader  disagree 
with  the  writer  on  this  point,  he  cannot  think  the  ultimate 
results  favorable.     (Fig.  20.) 

Fig.  18.  Fig.  19. 


Fig.  18.— The  form  of  the  Venus  de  Medici ;  beautiful  to  the  eye,  graceful  in  move- 
ment,  healthful,  and  long-lived. 

Fig.  19.— The  compressed  chest  of  mistaken  taste  ;  pity-causing,  ungraceful,  dis- 
proportioned ;  productive  of  ill  health,  deformity,  a  sallow  complexion,  premature 
wrinkles,  and  untimely  death. 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  47 

Fig.  20. 


Fig.  20.— 1, 1  represents  the  spinal  column  or  back-bone  very  much  curved,  causing 
the  right  shoulder  to  be  very  prominent. 

135.  Fig.  20  is  of  course  an  exaggerated  view  of  the  or- 
dinary effect  of  tight  dress,  but  worse  deformities  frequently 
occur.      Within  the  ribs  are  found  organs,  which  are  both 
compressed  and  displaced  by  lessening  the  waist.     To  dimin- 
ish the  evil,  and  give  these  parts  as  much  room  as  possible, 
nature  causes  the  upper  part  of  the  chest  to  yield. 

136.  In  the  first  place,  this  causes  square  shoulders,  in- 
stead of  the  graceful  "  falling"  shoulders  so  much  admired  ; 
or  the  shoulders  will  be  prominent — what  is  called  "  round,'7 
and  much  disliked.     From  the  constant  size  and  firmness  of 
the  liver,  on  the  right  side,  while  on  the  left  the  stomach  is 
sometimes  full,  sometimes  empty,  the  effect  of  pressure  will 
be  greater  on  the  right  side. 

137.  In  the  second  place,  there  will  be  a  greater  "shrug" 
or  projection  of  the  right  shoulder  than  of  the  left,  also  a  dis- 
placement of  the  spinal  column,  towards  the  right  shoulder. 
These  deformities  render  others  necessary,  that  the  system 
may  be  balanced.     The  head  is  inclined  to  the  left,  while  the 
back-bone,  in  the  loins,  is  displaced  in  the  same  direction. 
The  hips  are  distorted,  and  the  heads  of  the  thigh  bones  can- 
not be  opposite  each  other.      Can  the  form  of  such  a  person 
be  beautiful,  or  the  movements  graceful  ? 


48  ORGANS  OP  VOLUNTARY  MOTION.  [CHAP.  I. 

138.  During  the  day  a  person  grows  shorter,  while  the 
height  is  restored  by  repose  during  the  night.     A  French 
physiologist  says,  a  son  of  his,  during  a  single  night's  dance, 
lost  an  inch  of  stature,  which  he  regained  in  two  days.    This 
is  owing  to  the  elastic  nature  of  the  cartilages,  especially 
those  of  the  back,  and  the  restoring  processes  which  are  con- 
tinually taking  place  in  all  parts  of  the  body. 

139.  To  sit  or  stand,  most  of  the  time,  with  the  back  in  a 
curved  position,  will  tend  to  produce  permanent  comparative 
thinness  of  one  side  of  the  cartilage,  and  consequent  deformi- 
ty ;  while  on  the  other  hand,  a  variety  of  exercise  in  a  vari- 
ety of  positions,  will  not  only  prevent  deformity,  but  from  use, 
give  a  suppleness,  vigor,  and  health  to  the  cartilages,  which 
can  be  obtained  in  no  other  way. 

140.  To  sit,  stand,  or  lie,  in  almost  any  position  which 
gives  comfort,  cannot  be  productive  of  harm,  if  other  posi- 
tions be  frequently  taken.     No  class  of  people  are  straighter 
than  the  tailor,  who  sits  much  of  the  time  in  a  curved  posi- 
tion ;  but  knowing  that  the  fit  of  his  coat  is  an  advertisement 
of  his  skill,  as  soon  as  he  is  off  "  the  board  "  he  straightens 
himself. 

141.  A  continued  crooked  posture  is  not  to  be  recom- 
mended, neither  is  a  lounging  attitude  always  to  be  chided. 
Deformity  is  frequently  caused  by  nature,  to  prolong  the  life 
which  tight  clothing  tends  to  shorten ;    it  cannot  therefore 
be  remedied  by  the  oft-repeated  advice  to  "sit  straight;"  na- 
ture will  remove  the  deformity  as  soon  as  the  cause  for  which 
it  was  produced  is  removed.* 

142.  The  ligaments,  cartilages,  and  other  parts  are  of 

*  Experience  has  testified,  that  the  tight  clothing,  supports,  and  di- 
rections to  "  sit  up,"  without  exercise,  heretofore  used,  with  hard  seats, 
straight-backed  chairs,  and  no  allowance  of  easy  positions,  have  most 
signally  failed  to  accomplish  the  desired  object ;  and  as  it  seems  reason- 
able to  trace  the  general  deformity  to  these  very  things,  will  it  not  be 
well  to  try  something  else  ?  A  new  course  cannot  be  worse. 


SEC.  1.]  BONES,  CARTILAGES,  AND  LIGAMENTS.  49 

such  a  nature,  when  the  system  is  "  growing  fast,"  that  easy 
seats,  chairs,  rocking-chairs,  sofas,  and  a  reclining  and  sup- 
ported  position,  will  be  often  required,  to  give  rest  and 
strength.  I  never  saw  an  Indian  sit  erect,  and  the  cat 
and  dog  repose  themselves  much.  It  is  neither  the  curved 
position  which  does  harm,  nor  the  erect  position  that  gains 
benefit ;  but  any  position  too  often  indulged  in,  or  too  long 
continued,  produces  evil  results,  while  a  variety  of  positions, 
and  all  kinds  of  exercise,  give  beauty  and  health  to  the  form, 
and  vigor  and  gracefulness  to  the  movements. 

143.  If  deformity  exist,  can  the  exertion  of  force  merely, 
effect  a  cure  ?  What  will  prevent  the  recurrence  of -the  de- 
formity, when  the  force  is  removed  ?  Nothing.  Experience 
has  proved,  that  the  end  is  worse  than  the  beginning.  The 
reasonable  use  of  any  part  improves  it ;  disease  enfeebles  it. 
Exercise,  gentle  but  gradually  increased,  is  the  required 
means  for  curing  deformities.  Years  of  patient  persever- 
ance will  sometimes  be  necessary,  to  gain  the  rich  reward. 

144.  When  force,  supports,  and  exercise  have  been  com- 
bined, to  effect  cures  of  deformities,  the  cure,  if  effected, 
should  have  been  attributed  to  the  exercise,  which  not  only 
cured  the  deformity,  but  also  overcame  the  effect  of  the  force 
and  supports. 

145.  Horseback  riding  is  one  of  the  best  kinds  of  exer- 
cise, or  riding  in  an  easy  carriage,  the  use  of  dumb-bells,  the 
elastic  exerciser,  and  other  specific  exercises  which  in  the 
judgment  of  a  skilful  physician  are  best  adapted  to  correct 
the  deformity.  The  ordinary  deformity  of  round  shoulders, 
caused  by  neglect,  can  be  corrected  in  a  few  weeks,  by  exer- 
cise every  morning  for  five,  ten,  or  fifteen  minutes,  with  the 
perfect  exerciser,  dumb-bells,  or  throwing  a  chair  around  the 
head,  and  the  like. 


50  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 


SECTION  2. — Muscles,  Tendons,  fyc. 

146.  The  muscles  are  what  is  usually  called  the  lean 
meat.      The  tendons  are  the  pearly  white,  strong  parts,  ter- 
minating the  muscles,  and  connecting  them  with  the  parts 
upon  which  they  act. 

147.  The  appearance  of  these  will  be  well  understood  by 
examining  the  "  drum-stick  "  of  a  fowl,  and  the  cords  which 
extend  to  the  claws,  so  amusing  to  children. — 

148.  If  the  cord  upon  one  side  be  drawn,  the  claws  will 
be  shut ;    if  the  cord  upon  the  other  side  be  drawn,  and  the 
first  slackened,  the  claws  will  be  opened. 

149.  If  both  cords  be  drawn  to  an  equal  degree,  the  claws 
will  be  firmly  held  in  any  position  where  they  are  placed. 

150.  In  the  living  bird,  it  is  the  contraction  and  relaxa- 
tion of  the  muscles  in  the  leg  above,  which  draws  the  cords 
acting  upon  the  claws,  either  causing  them  to  move  or  re- 
taining them  in  any  desirable  attitude. 

151.  The  first  use  of  the  tendon  is  evident;    for  if  the 
muscles  had  continued  down  to  the  foot,  it  would  have  been 
so  clumsy  as  to  render  it  unfit  for  use ;  and  again,  the  fleshy 
muscle  could  not  form  so  strong  a  unison  with  the  bone,  as  to 
resist  its  own  action. 

152.  The  use  of  the  muscles  is  also  evident,  viz.  to  pro- 
duce motion  of  the  various  parts  of  the  frame,  and  retain 
them  in  desirable  attitudes ;  for  though  the  ligaments  are  ar- 
ranged so  as  to  prevent  motion  in  certain  directions,  they 
have  been  designed  to  permit  it  in  others,  flexion  in  the  per- 
mitted direction  being  caused  or  restrained  by  the  muscles.* 

*  The  frame  being  perfect,  in  respect  to  its  structure,  a  beautiful  form 
and  gracefulness  of  action  depend  entirely  on  the  muscles.  In  this  sec- 
tion, therefore,  especial  attention  will  be  given  to  explain  what  is  for  the 
good  or  ill  of  the  muscles ;  for  it  is  not  only  proper,  but  our  duty,  to  do 
all  in  our  power  to  improve  personal  beauty,  both  because  in  all  that  sur- 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  51 

153.  To  fulfil  these  duties,  it  is  requisite  that  they  be 
numerous,  contract  and  relax  with  promptitude,  and  with  a 
greater  or  less  degree  of  power ;    that  they  should  combine 
their  action  or  oppose  each  other,  or  act  in  harmonious  suc- 
cession. 

154.  Their   ability   to   answer  these   requirements   de- 
pends upon  their  structure,  number,  size,  their  position  and 
mode  of  attachment,  the  passage  of  blood  through  them, 
their  exercise,  and  the  action  upon  them  of  certain  influences 
called  nervous. 

155.  By  nature,  the  muscles  are  perfect  in  all  respects; 
but  their  condition  depends  so  much  upon  their  treatment,  and 
this  is  so   faulty,  that  they  are  usually  very  deficient  in  the 
fulfilment  of  their  important  duties. 

156.  Structure.     This  is  seen  by  observing  a  piece  of 
lean  boiled  salt  pork,  salt  fish,  or  almost  any  cooked  lean 
meat.     It  will  be  noticed  as  composed  of  fleshy  strings,  easily 
separated  in  one  direction ;    in  doing  which,  a  very  delicate 
sheet-like  substance  will  be  seen  clinging  to  and  uniting  the 
separating  parts,  somewhat  loosely  with  each  other.     This  is 
called  cellular  substance  or  membrane. 

157.  With  proper  instruments,  the  fleshy  strings  so  easily 
perceived  can  be  subdivided,  till  those  will  be  found  not  as 
large  as  a  spider's  thread.     These  are  covered  with  a  sheath 
proportionably  delicate,  which  extends  beyond  the  fleshy  fibre, 
and  with  the  cellular  substance  connecting  the  fibres,  is  con- 
densed into  tendon. 

158.  Hundreds  or  thousands  of  these  sheathed  fibres  are 
gathered  into  a  bundle,  and  covered  with  a  sheath  somewhat 
thicker  than  the  first,  forming  what  is  called  a  fasciculus. 


rounds  us,  and  in  the  functions  of  the  human  system,  we  have  evidence 
that  the  Creator  intended  every  thing  should  be  beautiful  and  attractive, 
and  because  what  really  improves  or  obtains  beauty  is  equally  influential 
in  gaining  and  preserving  health.- 


52  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Few  or  many  of  these  covered  with  a  sheath,  called  a  fascia, 
form  a  muscle.  Several  muscles  covered  with  a  sheath, 
called  also  a  fascia,  form  the  arm.  Place  the  hand  upon  the 
lower  arm,  then  open  and  shut  the  fingers,  and  various  mus- 
cles will  be  perceived.  The  fascia  is  for  the  purpose  of 
binding  the  fibres,  fasciculi,  and  muscles  together,  when  they 
contract;  the  advantage  of  which  will  be  seen,  when  a  per- 
son  grasps  his  arm  with  the  hand  and  thereby  raises  a  greater 
weight. 

159.  The  fibres  in  any  fasciculus  are  parallel  and  act 
together ;  but  the  fasciculi  of  a  muscle  may  be  parallel  or 
otherwise,  and  may  or  may  not  act  together,  or  may  act  in 
succession.  Thus  some  of  the  muscles  are  fusiform  (Fig. 
21).*  By  this  arrangement,  the  attachments  of  the  muscle 
occupy  but  small  space,  and  the  neat  and  commodious  hand 
is  moved  with  great  power. 

Fig.  21. 


Fig.  21.— f,  t.  Tendons  of  a  fusiform  (spindle-shaped)  muscle. 

160.  Some  are  radiate,  as  the  sticks  of  a  fan  (Fig.  22). 
This  is  the  case  with  the  temporal  muscle,  the  thin  edge  of 
which  is  attached  to  the  side  of  the  head,  without  deforming 
it,  while  as  the  fibres  converge  toward  the  lower  jaw,  they 
are  received  in  a  hollow  of  the  skull.  The  trapezius  is  an- 
other example  (Lith.  plate  2).  This  was  evidently  thus  form- 
ed with  a  view  to  convenience  of  action,  as  well  as  personal 
appearance.  By  its  action  the  shoulder  is  drawn  upward,  back- 
ward, or  downward,  while  by  a  successive  contraction  of  its 
parts,  a  graceful  rotary  motion  is  given,  which  could  not  so 
well  have  been  obtained  in  any  other  way. 

f  The  stripes  on  the  figures  explain  the  direction  of  the  fasciculi. 


SEC.  2.]  MUSCLES,  TENDONS,  ETC. 

Fig.  22. 


Fig.  22.— Fan-shaped,  or  radiated  muscle. 

161.  In  some  instances  the  fasciculi  are  arranged  upon 
one  or  both  sides  of  a  tendon,  as  the  barbs  of  a  pen  (Fig. 
23).  By  this  arrangement  a  great  number  can  act  upon  tho 
same  point.  This  arrangement  is  particularly  seen  in  the 
leg,  where  a  great  amount  of  muscular  substance  must  act 
upon  small  points. 

Fig.  23. 


Fif.  S3.— Penniform  (pen-form)  muscl«. 

162.  In  some  instances  the  fasciculi  form  circular  mus- 
cles, orbiculares,  or  sphincters  (Fig.  24).  These  may  par- 
tially  or  wholly  close  any  opening  which  they  encircle ;  the 
mouth,  eyelids,  &c. 

Fig.  24. 


163.  In  some  portions  of  the  body  circular  fasciculi  are 
placed  by  the  side  of  each  other,  forming  a  muscular  tube 
(Fig.  25).  By  the  successive  contraction  of  these  rings, 
any  thing  can  be  moved  through  the  tube,  as  is  exhibited  in 
the  neck  of  a  horse  swallowing  water. 


64 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  25. 


Fig.  25. — Section  of  oesophagus,  or  meat-pipe,  a,  6,  Circular  fibres,   c  Shows  longi- 
tudinal fibres  in  another  layer  of  the  same  tube. 

164.  Sometimes  the  fasciculi  curve  around,  either  in  dis- 
tinct layers  or  interlacing  each  other,  so  as  to  form  a  muscu- 
lar pouch,  bag,  or  bladder  (Figs.  26  and  27).  By  the  con- 
traction of  the  muscular  substance  of  a  pouch,  its  contents 
will  be  expelled,  as  when  the  heart  throws  out  its  blood,  or 
by  the  alternate  contraction  and  relaxation  of  its  various 
parts,  its  contents  can  be  moved  about  in  it,  as  when  the  food 
is  digesting  in  the  stomach. 

Fig.  26. 


Fig.  26. — Stomach  muscles.  L  M,  One  layer  of  fibres  running  in  one  direction. 
C  M,  A  layer  running  in  another  direction.  E,  Lower  part  of  meat-pipe.  P,  Pylorua 
D,  Commencement  of  second  stomach. 

165.  The  number  of  the  muscles  is  about  four  hundred 
and  eighty.  The  number  will  vary  in  different  persons,  and 
according  to  the  plan  adopted  in  counting  them.  Some  per- 
sons divide  a  muscle  into  two,  of  which  others  make  but  one. 
Their  number  is  such,  that  by  the  action  of  some  one  or  its 
parts,  or  by  the  action  of  several  or  their  parts,  I  know  not  a 


SEC.  2.]  MUSCLES,  TENDONS,  ETC. 


Fig.  27. — Represents  the  heart  cut  open,  or  rather,  with  a  piece  removed,  the  thick 
sides  (o  n)  being  composed  of  muscular  fibres  interwoven  in  every  possible  directiou 

desirable  motion  that  cannot  be  performed,  muscles  only  being 
considered.     The  lithographic  plates  represent  most  of  them. 

166.  Size.     In  size,  the  muscles  are  extremely  various. 
The  six  which  produce  the  lively  motions  of  the  eye,  are  very 
delicate  and  beautiful (Fig.67)  while  the  glutei  are  very  large. 
Where  much  power  is  required,  the  muscle  will  be  large  if 
there  be  no  objection,  but  if  a  large  muscle  would  produce 
deformity  or  render  the  part  awkward  in  the  fulfilment  of  du- 
ties, a  small  muscle  will  be  found,  and  its  power  increased 
by  the  action  of  nervous  influence  upon  it.      In  some  con- 
stitutions, the  muscles  are  naturally  much  larger  than   in 
others. 

167.  In  every  person  the  muscles  will  increase  or  dimi- 
nish, within  certain  limits,  by  use  or  disuse ;    and  as,  in  any 
given  person,  the  larger  the  muscles  the  stronger,  so  ought 
every  person  who  wishes  strong  muscles,  to  exercise  the  back 
and  give  vigor  to  the  movements,  to  avoid  the  use  of  all  sup- 
ports which  throw  the  muscles  into  disuse,  enfeeble  them, 
and  produce  deformity. 

168.  To  gradually  require  more  and  more  of  any  part 
is,  therefore,  a  sure  way  to  increase  the  power  of  perform- 
ance, if  in  other  respects  proper  attention  be  given. 


66  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

169.  The  positions  of  the  muscles  can  only  be  appreci- 
ated after  a  consideration  of  three  kinds  of  ^evers,  represent- 
ed by  Figs.  28,  29,  and  30.  An  example  of  the  first  is  seen 
in  the  common  steelyard,  and  in  the  board  used  by  children 
in  playing  seesaw.  It  requires  a  very  heavy  boy  on  the  short 
end  of  the  rail  to  balance  a  light  boy  on  the  long  end,  and 
the  small  boy  moves  through  a  long  distance  in  the  same 
time  the  heavy  boy  moves  through  a  short  space. 

Fig.  28. 


Fig.  28.— P,W,  Lever.    P,  Power.    W,  Weight    F,  Fulcrum. 
Fig.  29. 


Pig.  29.— F,W,  Lever.    P,  Power.    W,  Weight.    F,  Fulcrum. 
Fig.  30. 


Fig.  30.— F,W,  Lever.    F,  Fulcrum.    W,  Weight.    P,  Power. 

170.  The  muscle  on  the  back  part  of  the  arm  (Fig.  31) 
corresponds  to  the  heavy  boy,  and  the  hand  to  the  small  one. 
By  a  slight  contraction  of  the  muscle,  the  hand  is  quickly 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  57 

moved  through  a  long  distance.  Extent  and  celerity  of  mo- 
tion  is  what  the  muscles  are  usually  called  to  produce.  But 
the  muscle  must  be  much  more  powerful  than  if  the  arm  had 
extended  in  the  dotted  line  (A  E),  and  the  muscle  had  been 
situated  in  the  dotted  lines  (A  S).  But  as  a  muscle  can 
only  shorten  to  a  given  degree,  viz.  about  one-third  its 
length,  the  motion  of  the  hand  would  have  been  very  limit- 
ed. What  an  awkward  thing  the  arm  would  have  been ! 

Fig.  31. 


Fig.  31.— Represents,  at  S,  the  ball  of  the  upper-arm  bone,  which  extends  to  the  el- 
bow at  E,  from  which  the  two  bones  (radius  and  ulna)  extend  to  the  wrist,  to  which 
the  hand  is  attached,  supporting  the  weight  (W)  T,  T,  represent  the  tendons,  and  B, 
the  belly  of  the  muscle  upon  the  front  part  of  the  arm,  attached  at  L  to  the  lower-arm, 
and  at  O  to  the  shoulder.  On  the  back  of  the  upper-arm  is  seen  the  muscle  attached 
to  the  shoulder  above,  and  to  the  projecting  point  of  the  elbow  below  This  point,  it 
will  be  remembered,  is  a  part  of  the  lower-arm  bone— the  ulna.  When,  therefore, 
the  muscle  on  the  front  of  the  arm  contracts,  the  muscle  upon  the  back  must  lengthen. 
When  the  muscle  upon  the  front  part  of  the  arm  contracts,  the  third  kind  of  lever  is 
represented ;  for  the  fulcrum  is  at  the  elbow,  and  the  power,  viz.  the  muscle,  acta  be- 
tween the  fulcrum  and  weisht,  and  the  nearer  the  weight  the  power  acts,  the  easier  is 
the  weight  raised.  If,  therefore,  the  power  or  muscle  should  act  in  the  dotted  line 
above  the  arm,  a  very  small  muscle  would  be  sufficient  to  accomplish  what  is  now 
done  by  O,  I.  But  it  would  require  as  long  to  shorten  the  muscle  an  inch  in  one  po- 
sition as  in  the  other;  but  the  contraction  of  O,  I,  one  inch,  will  produce  extensive 
motion  of  the  hand,  while  an  inch  contraction  of  the  dotted  line  would  raise  the  hand 
but  one  inch.  When  the  muscle  on  the  back  of  the  arm  is  contracted,  a  lever  of  the 
first  kind  is  represented.  The  elbow  is  the  fulcrum,  and  is  between  the  power  and 
weight ;  the  action  of  the  power,  viz.  the  muscle  on  the  back  of  the  arm,  draws  the 
projecting  part  of  the  elbow  up  ;  and  the  other  extremity  of  the  same  bone,  viz.  the 
wrist,  must  be  carried  down.  If  the  point  of  the  elbow  projected  to  A,  and  the  muscla 
acted  in  the  direction  of  the  dotted  lines  (S,  A),  it  would  have  greater  "  purchase  p 
but  if  it  contracted  an  inch,  it  would  move  the  hand  an  inch  only,  while  now,  if  it  con- 
tract an  inch,  it  will  sweep  the  hand  through  great  space,  and  of  course,  very  quickly. 
The  muscle  also  acts  with  greater  power  in  the  first  part  of  its  contraction,  thin  when 
its  degree  of  contraction  is  near  its  limit. 

171 .  An  example  of  the  second  lever  is  seen  when  a  person 
attempts  to  raise  a  barrel  of  flour  on  to  its  head,  by  lifting  at  one 
end  while  the  other  is  on  the  ground.  The  muscle  acting  upon 


58  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

the  heel  (Fig.  32)  is  the  power,  the  foot  the  lever,  the  ground 
where  the  toes  rest  the  fulcrum,  and  the  weight  rests  upon 
the  ankle.  Here,  the  greater  the  distance  of  the  power  from 
the  weight,  in  proportion  to  the  length  of  the  lever,  the  great, 
er  the  effect.  If  the  distance  be  short,  the  power  must  be  the 
greater.  The  muscles  which  raise  the  weight  of  the  body, 
when  we  stand  on  tiptoe,  must  be  very  powerful,  and  they 
are  so,  both  by  size  (Lith.  plate  1)  and  the  reception  of  ner- 
vous influence. 

Fig.  32. 


Fig.  32.— Represents  the  foot  upon  which  the  weight  of  the  body  rests  through  the 
oone  (1),  which  may  be  called  weight ;  M,  a  muscle,  is  the  power,  for  by  contraction 
it  raisea  the  weight ;  2,  at  the  great  toe  joint,  being  the  place  of  the  fulcrum. 


172.  An  example  of  the  third  lever  is  seen  when  we  at- 
tempt  to  close  a  window  blind  by  seizing  it  near  the  hinge ; 
the  nearer  the  hinge  the  hand  is  applied,  the  greater  the  power 
required,  but  the  less  the  motion.  The  part  of  the  body  most 
frequently  described  to  illustrate  this  lever,  is  the  forearm 
(Fig.  31).  The  muscle  upon  the  front  part  of  the  upper-arm 
is  the  power,  the  joint  is  the  fulcrum,  the  forearm  is  the  lever, 
the  hand  is  the  weight.  If  the  muscle  had  been  attached  at 
R,  and  been  situated  in  the  line  T  R,  it  would  have  been  like 
putting  the  hand  to  the  outer  edge  of  the  blind.  The  force 
required  to  raise  the  hand  would  be  but  slight ;  it  would  have 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  59 

been  raised,  however,  but  slowly,  and  could  have  been  raised 
but  about  one-third  the  length  of  T  R. 

173.  Most  of  the  muscles  act  disadvantageously  as  it  re- 
gards expenditure  of  power,  but  the  system  is  compact,  beau- 
tiful, symmetrical,  and  the  motions  are  performed  with  agility 
and  to  the  extent  required.      In  some  cases  the  muscles  act 
with  the  most  complete  advantage  of  position. 

174.  Some  of  the  muscles,   instead  of  acting  between 
bones,  are  so  situated  as  to  act  upon  other  parts  to  which  they 
are  attached.     The  "  occipito  frontalis  "  (Lith.)  acts  upon  the 
skin  of  the  head,  moving  the  scalp,  and  is  called  a  cutaneous 
or  skin  muscle.      There  are  others  of  a  similar  character  ; 
some  act  upon  the  fascia,  as  the  Tensor  vagina  femoris  (Lith.), 
rendering  them  tense. 

175.  The    tendons    of   certain    muscles    pass    through 
loops  or  pullies,  in  such  manner  as  to  produce  motion  in  a 
direction  quite  different  from  that  in  which  the  muscle  con- 
tracts ;    the  "  superior  oblique  "  of  the  eye  is  an  example 
(Fig.67);  the  "  digastricus,"  or  "  two-bellied  muscle,"  is  an- 
other instance— one  extremity  is  attached  to  the  skull  just 
below  the  ear ;  it  extends  down  to  the  side  of  the  U-like  bone 
at  the  top  of  the  windpipe,  where  its  central  tendon  is  confined 
by  a  tendinous  loop ;    its  front  extremity  is  then  attached  to 
the  inner  side  of  the  jaw  near  the  middle.     Its  use  is  to  de- 
press the  lower  jaw. 

176.  Bands  confine  the  tendons  of  other  muscles  ;  for  in- 
stance, the  one  about  the  wrist  called  an  annular  ligament 
(Lith.).    A  similar  one  is  found  passing  from  the  inside  to  the 
outside  of  the  ankle,  in  front,  confining  the  tendons  that  raise 
the  toes. 

177.  Some  of  the  tendons  pass  through  or  under  each 
other.     The  muscle  which  bends  inward  the  last  joint  of  the 
fingers,  is  situated  below  the  muscle  which  acts  upon  the 
middle  joints  ;  the  tendons  of  this  last  divide  at  their  lower 


00  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

extremities,  one  part  being  attached  to  one  side  of  the  bone, 
the  other  division  to  the  other  side,  and  the  tendons  for  the 
last  joint  pass  through  between,  whereby  the  fingers  are 
neater  and  more  useful.  Again,  the  tendons  of  several  mus- 
cles pass  round  certain  bones,  or  are  situated  in  grooves,  as 
the  tendon  of  the  muscle  on  the  outside  of  the  fibula  (Lith.), 
which  passes  down  under  the  foot,  and  is  attached  just  back 
of  the  great  toe.  Thus  beauty  and  utility  are  every  where 
combined. 

178.  Certain  muscles  pass  across  each  other,  as  the  tai- 
lor's muscle  or  sartorius,  by  which,  with  the  action  of  others, 
the  leg  is  drawn  up,  as  when  a  tailor  sits  down  on  his  board. 
The  fasciculi  of  certain  others  are  twisted,  so  to  speak,  and 
cross  each  other,  as  in  the  pectoralis  major  (Lith.).      The 
contraction  of  the  lower  portion  of  this  muscle  would  draw 
the  shoulder  down  and  forward,  and  the  nearer  it  was  at- 
tached to  the  shoulder,  the  more  effectual ;  while  the  contrac- 
tion of  the  upper  part,  would  throw  the  arm  across  the  chest, 
and  the  further  from  the  joint,  the  more  effectual.      But  the 
muscle  must  stretch  down  upon  the  arm  but  a  short  distance, 
or  it  would  produce  awkwardness.     How  ingenious,  then,  the 
contrivance  which  exists! 

179.  The  position  of  the  muscles  is  such,  that  motion  is 
rarely  produced  by  the  action  of  a  single  muscle,  but  usually 
by  the  "  composition  of  forces,"  which  will  be  understood,  if 
two  boys  attach  two  strings  to  a  chair  upon  the  floor,  and  then 
stand  in  front  of  it,  some  distance  apart.      If  one  only  pull 
his  string,  the  chair  will  be  drawn  toward  him ;  if  each  pull 
his  string  at  the  same  time,  the  chair  will  move  toward  a 
point  between  them,  which  will   be  nearer  to  him  who  exerts 
the  most  force.      If  more  boys  be  furnished  with  strings,  the 
comparison  will  be  more  perfect ;  and  if  one  boy  exert  more 
force  one  moment,  and  another  the  next,  the  chair  will  de- 
scribe a  variety  of  lines. 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  61 

180.  The  application  of  this  principle  in  the  action  of  the 
muscles  is  constantly  required,  but  exceedingly  difficult,  as 
the   force  with  which  the  muscle  contracts  must   be  almost 
constantly  varying  in  the  production  of  almost  any  motion. 

181.  The  attachment  of  the  muscles,  except  to  the  parts 
they  are  intended  to  act  upon,  is  but  slight,  as  can  be  seen, 
or  felt  rather,  in  the  case  of  the  neck  cords,  which  hardly  dis- 
turb the  parts  which  surround  them.      They  are,  however, 
attached  in  the  strongest  manner  at  their  extremities.     Ob- 
serve  the  force  with  which  the  muscle  upon  the  front  part  of 
the  arm  acta  without  in  the  least  injuring  its  attachment.    By 
its  connection  with  the  lever,  if  one  hundred  pounds  be  raised 
in  the  hand,  the  power  exerted  by  the  muscle  must  be  twen- 
ty-two and  one-half  times  as  great,  or  sufficient  to  raise  a 
"  heavy  ton.'7     Other  muscles  exert  greater  power  still.     I 
have  seen  a  man  lie  down  upon  his  back  under  a  cart,  place 
his  feet  against  the  axle,  and  by  straightening  his  limbs  raise 
fifteen  hundred  pounds'  weight  from  the  ground. 

182.  The  position  of  the  muscles  is  such,  that  if  one  con- 
tracts another  must  relax.     When,  therefore,  we  consider  the 
effects  of  contracting  a  muscle  or  class  of  muscles,  we  must 
also  consider  the  effects  of  relaxation  of  its  opponents ;    and 
when  we  look  for  what  will  favor  the  contraction  of  muscles, 
we  must  consider  what  will  favor  the  relaxation  of  its  anta- 
gonists. 

183.  Contraction  and  relaxation  of  the  muscles  are  attend- 
ed by  a  corresponding  change  of  their  substance. 

184.  This  is  proved  by  the  change  which  takes  place  in 
the  blood  passing  through  a  muscle,  by  the  increased  appetite 
and  requirement  for  food  attendant  upon  action  of  the  mus- 
cles, or  by  an  examination  of  the  muscles  of  an  animal  which 
has  been  driven  or  hunted  to  death. 

185.  If  the  muscle  undergo  a  change,  two  things  are 
necessary  ;.  that  the  portion  of  the  muscle  which  by  its  action 


62  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

has  become  unfit  for  use  be  removed,  and  its  place  supplied 
by  new  material.     Hence  the  necessity  for  a 

186.  Free  flow  of  blood.    By  the  current  of  blood  through 
the  muscle   the  decomposed  substance  is  removed,  and  the 
substance  to  recompose  the  muscle  is  brought. 

187.  Pressure  upon  any   part  checks  the  flow  of  blood, 
and  of  course  must  be  seriously  injurious  to  the  muscles  ;  to 
those  of  the  young,  for  the  muscles  then  need  an  extraordi- 
nary supply  to  cause  them  to  grow,  as  well  as  to  repair  the 
effects  of  use,  so  do  the  muscles  of  all  persons,  that  they  may 
be  endowed  with  the  vigor  necessary  for  the  fulfilment  of 
their  duties. 

188.  Notice  the  muscles  of  the  back  (Lith.),  and  decide 
if  the  child  can  be  gifted  with  a  fine  form,  when  the  clothing 
prevents  the  free  circulation  of  the  necessary  blood.      Can 
the  young  lady  be  easy  and  graceful,  when  pressure  upon 
the  muscles  of  the  chest,  checks  the  flow  of  the  repairing  sub- 
stance, without  which  the  muscles  must  be  colorless,  flabby, 
and  weak,  and  incapable  of  performing  their  duties  ? 

189.  Rubbing  any  part  increases  the  flow  of  blood  ;  hence 
the  benefit  of  rubbing  the  muscles.     It  causes  the  changes  to 
take  place  in  them  more  speedily,  and  gives  relief  to  fatigue. 

190.  Fatigue  is  for  the  purpose  of  warning  us,  when  the 
muscle  has  experienced  so  much  decomposition  as  to  render 
it  proper  to  grant  repose  and  time  for  its  repair ;    it  is,  there- 
fore, a  friend  whose  hints  should  be  regarded.      The  farmer 
who  uses  stimulating  drinks,  for  the  purpose  of  overcoming 
fatigue,  does  overcome  the  feeling  of  fatigue,  but  benefits  not 
the  muscle.     If  he  go  on  to  labor,  he  injures  the  muscle  and 
profits  not  himself,  as  attacks  of  rheumatism  and  the  stiffness 
felt  in  his  declining  years  will  fully  prove. 

191.  Rubbing  the  muscles  relieves  from  fatigue,  by  be- 
nefiting them ;    hence  why  every  laboring  man  should  spend 
five,  ten,  or  fifteen  minutes,  morning  and  evening,  in  doing 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  63 

for  himself  what  experience  teaches  is  so  beneficial  to  the 
horse. 

192.  Rubbing  supplies  the  muscles  with  blood,  which 
shall  increase  their  size  ;  hence  why  children  should  be  tho- 
roughly and  daily  rubbed  from  head  to  foot ;  for  why  should 
the  colt,  worth  only  a  hundred  dollars,  be  groomed  so  much 
better,  that  it  may  be  fitted  for  the  market,  than  the  child, 
whose  welfare  is  beyond  price  ? 

193.  Rubbing  supplies  to  the  muscles  that  blood,  by  the 
action  of  which  a  fine,  healthy  condition  is  preserved ;  hence 
why  those  who  wish  to  be  graceful  should  rub  the  system 
from  head  to  foot,  at  least  once  per  day ;  for  why  should  the 
animal  which  the  young  lady  rides,  have  daily  attention  paid  to 
him  in  this  respect,  that  he  may  prance  with  ease  and  make  a 
fine  appearance,  while  she,  whose  beauty  is  so  much  more 
attractive,  is  neglected  ? 

194.  Rubbing  supplies  the  muscles  with  the   material 
which  can  restore  their  health  and  power  of  action.     To  the 
deformed,  to  the  palsied,  to  those  whose  muscles  are  withered 
or  shrunk  from  disuse,  the  hint  is  sufficient.      To  the  posi- 
tively diseased  by  palsy  it  may  do  but  little  good — it  can  do 
no  harm. 

195.  Contraction  and  relaxation  of  the  muscles  has  in 
one  respect  the  same  effect  as  rubbing,  the   blood-vessels 
being  constructed,  as  hereafter  described,  so  that  the  flow 
of  blood  must   always   be   onward,  and   never  backward. 
When  a  muscle  contracts,  its  blood  is  pressed  out  from  it ; 
when  it  relaxes,  there  is  a  rush  of  blood  into  it ;  hence  why 
the  alternate  contraction  and  relaxation  are  necessary ;  for  a 
muscle  remaining  long  contracted,  is  undergoing  decompo- 
sition without  receiving  blood  to  repair  itself.      The  severest 
fatigue  is  therefore  felt,  to  compel  us  to  desist,  or  the  muscle 
would  be  affected  beyond  restoration,  as  has  sometimes  oc- 
curred, when  a  feeble  person  has  been  called  up,  to  save  his 


64  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

property  from  fire — excited  by  the  danger,  he  failed  to  heed, 
did  not  even  notice  the  warning  of  fatigue,  till  exhausted, 
he  was  overcome,  and  years  failed  to  effect  a  recovery. 

196.  In  very  rapid  contraction  of  the  muscle,  a  state  ap- 
proaching continued  contraction  is  produced.     The  blood  has 
hardly  time  to  gush  through  the  muscle,  perhaps  does  not 
visit  every  part,  before  it  is  sent  on  by  re-contraction.    Hence 
why  a  horse  bears  better  to  draw  a  heavy  load  slowly,  than 
a  light  load  quickly.     Stage  horses  improve  in  "  muddy  go- 
ing," though  longer  on  the  road, — their  muscles  contracting 
slowly,  there  is  time  allowed  for  their  repair. 

197.  Exercise  improves  the  condition  of  the  muscle,  by 
causing  its  bloodvessels  to  enlarge,  both  transiently  and  per- 
manently.     There  is  a  power  operating  in  the  healthy  sys- 
tem, to  adapt  each  part  to  the  fulfilment  not  only  of  its  ordi- 
nary, but  extraordinary  duties. 

198.  From  what  has  been  said,  it  is  evident  the  muscles 
require  more  blood  when  in  action  than  when  in  repose. 
The  very  exercise  of  the  muscle  answers  the  requirement  in 
part;    the  increased  action  of  the  heart,  as  hereafter  shown, 
is  an  advantage  ;    but  the  bloodvessels  of  the  exercised  mus- 
cles are  enlarged  for  the  time,  and  by  repeated  exercise  the 
enlargement  is  made  permanent,  though  an  additional  en- 
largement takes  place  at  the  time  of  action. 

199.  To  strengthen  the  muscles,  therefore,  exercise  must 
be  gentle,  repeated  often,  and  very  gradually  increased.     If 
it  be  violent  at  first,  the  muscle  is  injured.     Those  who  speak, 
therefore,  but  once  or  twice  per  week,  feel  fatigue,  while  those 
who  speak  every  day  find  it  a  pleasure.     The  person  who  is 
deformed  from  weakness  of  the  muscles,  exerts  himself,  and 
finds  no  relief,  but  harm  to  follow. 

200.  The  sick  must  be  especially  careful,  for  the  power 
referred  to,  as  adapting  all  the  organs  to  their  exigencies, 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  65 

is  feeble;    and  the  muscles  become  strong  very  gradually 
in  such  a  person, — it  is  an  exceedingly  easy  thing  to  overdo. 

201.  But  rest  seems  as  necessary  as  exercise.     It  is  evi- 
dently so,  for  repose  is  eagerly  sought  after  vigorous  action, 
and  a  sound  sleep  follows.     Slight  repose  is  necessary  after 
each  contraction  of  the  muscle,  that  the  blood  may  be  allowed 
to  flow  through  it  and  communicate  vigor  by  renewal,  but  yet 
the  decomposition  does  not  seem  to  be  entirely  compensated. 

202.  When  the  system  is  "  growing,"  rest  seems  espe- 
cially necessary  •  nature  causes  it  to  be  sought,  and  follow- 
ing her  hints,  the  system  will  not  be  subjected  to  very  arduous 
labor,  and  a  reclining  posture  will  be  allowed.     Alarm  will 
not  be  felt  if,  at  such  times,  the  chest  and  head  fall  forward 
somewhat.     This  will  be  "outgrown,"  if  no  force,  supports, 
or  tight  clothing  be  used,  and  a  plenty  of  exercise  in  the  open 
air  be  allowed.      The  power  which  acts  upon  the  muscle  to 
produce  all  these  results,  is  called  the 

203.  Nervous  influence.      Whether  this  be  of  the  same 
nature,  when  we  see  it  exerted  on  the  heart  and  causing  it  to 
beat,  as  when  we  see  its  effect  in  the  contracting  muscle  of 
the  arm,  and  when  its  action  is  seen  upon  the  bloodvessels  of 
the  muscle  enlarging  or  diminishing  them,  is  not  known. 
Whether  there  be  one  fountain  or  several  from  which  it  is 
derived,  is  not  known  with  certainty. 

204.  Some  of  its  effects  are  directly  influenced  by  ttie 
mind,  some  only  indirectly.      The  muscles  are  therefore  di- 
vided into  three  classes ;  those  whicfc  in  health  are  contracted 
by  the  nervous  influence  under  control  of  the  will,  such  as 
the  muscles  of  the  arm,  and  are  called  the  voluntary  muscles ; 
those  which  are  never  directly  acted  on  by  the  will,  as  the 
heart,  and  called  the  involuntary  muscles ;  those  over  which 
the  mind  ordinarily  exerts  no  control,  but  over  which  within 
limited  bounds  it  can,  as  the  muscles  concerned  in  breathing, 
and  called  mixed  muscles. 


66  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

205.  At  present  the  muscles  of  the  first  class  are  under 
consideration.     The  nervous  influence  which  acts  upon  them 
is  derived  from  the  brain  through  the  nerves.     To  study  these 
will  therefore  be  the  next  step.      But  first,  a  view  may  be 
taken  of  the  known  effects  of  the  nervous  influence  on  the 
muscles. 

206.  Its  first  effect  is  to  add  immensely  to  the  cohesive 
attraction  of  the  substance  of  the  muscle  in  one  direction. 
Out  of  the  body  a  muscle  is  separated  by  a  small  weight,  but 
in  life  it  is  capable  of  exhibiting  immense  force  without  be- 
ing injured  in  the  slightest  degree. 

207.  The  degree  to  which  a  muscle  shortens  and  the 
power  which  it  exerts,  depends  not  on  its  size,  merely,  but  on 
the  nervous  influence  it  receives.* 

208.  Whether  the  relaxation  of  the  muscle  is  an  active 
operation,  or  takes  place  by  the  withholding  merely  of  the 
influence  which  caused  its  contraction,  is  uncertain. 

209.  The  action  of  this  influence  depends  much  upon 
habit,  as  is  seen  by  rotating  the  shoulder  by  means  of  the 
"  trapezius  "  (Lith.)  upward,  backward,  and  downward,  and 
then  trying  to  rotate  it  downward,  backward,  and  upward. 
The  muscle  is  as  ready  to  contract  one  way  as  the  other,  but 
we  are  in  the  habit  of  exerting  the  nervous  influence  upon  it 
only  in  one  way.      How  awkward  the  combined  movement 
of  the  fingers  when  the  first  tune  is  attempted  on  the  piano-— 

by  practice  how  graceful ! 

* 

*  It  has  been  somewhere  stated,  that  if  a  small  muscle  be  ordinarily 
called  on  to  perform  great  labor,  it  is  supplied  with  a  large  nerve.  But 
we  see  every  day,  that  a  greater  or  less  degree  of  nervous  influence  is 
exerted  through  the  same  nerve,  and  with  the  same  instantaneous  effect. 
Nor  is  there  any  proof  or  assertion,  of  which  we  are  aware,  that  when 
a  muscle  increases  to  twice  its  former  size  and  many  times  its  former 
power,  the  number  of  nervous  fibres  passing  to  it  from  the  brain  are  in- 
creased.' My  own  opinion  is,  therefore,  that  if  a  nerve  be  distributed 
through  a  muscle  so  as  to  be  able  to  cause  decomposition  and  contraction 
of  all  its  parts,  it  is  sufficient,  and  that  any  amount  of  influence  may  be 
transmitted  through  it. 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  67 

210.  Many  times  indeed,  muscles  cannot  act,   because 
they  have  never  been   sufficiently  exercised  ^    but  besides 
this,  the  perfection  of  gracefulness  is  the  acquired  ability  to 
exert  the  nervous  influence  upon  any  muscle  or  part  of  a 
muscle,  upon  any  class  or  parts  of  a  class  of  muscles^  ;n- 
stantaneously.     It  is  this  which  confers  the  power  of  singing 
any  combination  of  notes,  or  speaking  any  combination  of 
sounds,  whether  of  our  own  or  a  foreign  land.      It  is  an  al- 
most insurmountable  task,  but  practice  makes  perfect. 

211.  The  effect  of  habit  is  likewise  seen  in  the  muscles 
of  expression,  as  those  of  the  face  (Lith.)  are  called  ;  though 
at  times  every  muscle  of  the  body  exhibits  the  fervor  of  the 
mind.      Almost  any  state  of  mind  will,  from  habit,  exhibit 
itself  in  the  constant  action  of  certain  muscles,  even  when 
this  is  not  desired,  indeed  when  a  strong  effort  is  made  to 
prevent  it.      The  miser,  who  spends  his  time  at  home  in 
counting  his  money,  will  betray  his  avarice  in  his  face,  even 
when  dropping  his  hypocritical  alms  in  the  church  box. 

212.  A  lovely  expression  is  to  be  obtained  only  by  main- 
taining a  lovely  state  of  mind.      Nature  never  supposed  a 
man  would  be  one  thing  and  wish  to  appear  something  else, 
but   judged   he  would    be   proud»x>f  showing  himself   as 
he  is. 

213.  As  all  real  beauty  is  in  the  mind,  and  matter  is  no- 
thing except  as  we  associate  the  action  of  mind  with  it ;  there  is 
nothing  so  attractive,  however  bad  the  complexion  or  homely 
the  features,  as  a  face  exhibiting  an  amiable  disposition,  a 
noble  and  cultivated  intellect.     The  tinge  of  beauty  on  the 
cheek  can  be  surpassed  by  the  inanimate  lily ;  the  dentist 
can  supply  the  deficiencies  of  nature  as  perfect  in  beauty 
as  her  own  works;  the  sculptor  can  give  us  perfection  of 
features  beyond  reality  :  it  is  the  mind  only  which  makes  the 
"human  face  divine." 

214.  The  muscles  being  thus  dependent  on  nervous  in- 


68  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

fluence  and  the  action  of  the  mind,  if  the  nervous  influence 
be  diverted  to  other  objects,  the  muscles  cannot  contract  with 
vigor,  nor  can  they,  without  the  energetic  action  of  the  mind. 
Those,  therefore,  who  hope  to  gain  benefit  from  exercise  by 
merely  exercising  the  body,  while  the  mind  is  deeply  en- 
grossed with  home  or  business  affairs,  will  be  disappointed. 
To  labor  or  exercise  in  a  way  that  engages  the  mind,  and 
also  produces  a  lively,  agreeable  disposition,  is  exceedingly 
important.  A  dull,  compulsory  walk,  is  not  the  thing. 

215.  The  laboring  man  will  also  perceive  that  mental 
cultivation  is  important  for  him,  if  he  would  labor  with  suc- 
cess.    He  who  reads  two  hours  per  day,  and  works  eight, 
will  accomplish  more  in  a  lifetime  than  he  who  labors  ten, 
and  does  not  devote  any  time  to  the  improvement  of  his  mind. 

216.  The  voluntary  muscles  are  also  active  involuntarily. 
That  they  can  be  so  is  evident  from  the  twitchings  seen  in 
chorea  or  St.  Vitus'  dance,  and  in  the  convulsions  of  disease, 
lock-jaw,  tetanus,   &c.      That  they  are  is  certain,  as,  if  ft 
muscle  be  cut,  the  wound  gapes ;  if  a  bone  be  displaced,  the 
greatest  force  to  be  overcome  in  "setting"  it, -is  the  involun- 
tary action  of  the  muscles  of  volition ;    if  a  person  walk, 
stand,  sit,  or  recline,  or  ev«n  repose  in  sleep,  the  constant  in- 
voluntary action  of  the  voluntary  muscles  is  required  to 
balance   the   system; — many   other  illustrations  might    be 
used. 

217.  Some  suppose  a  certain  degree  of  power  of  con- 
traction resides  in  the   muscle   itself,  which   seems  to   be 
exhibited  in  the  rigidity  of  the  muscles  after  death.      But, 
all  things  considered,  every  action  of  the  muscle  seems  to 
be  conferred  by  the  nervous  influence,  and  this  I  believe  is 
the  opinion  of  nearly  all  persons,  and  is  proved  by  the  ef- 
fects of  tobacco,  intoxicating  drinks,  fear  and  other  emo- 
tions of  the  mind,  and  of  disease  of  the  fountains  of  nervous 
influence. 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  69 

218.  The  power  and  certainty  with  which  the  involunta- 
ry contractions  of  the  voluntary  muscles  take  place,  seem 
dependent  but  very  slightly  upon  habit,  but  upon  the  health 
of  the  system  and  its  natural  constitution  ;  things  which  affect 
the  condition  and  energy  of  the  nervous  influence.      The 
power  of  exercising  this  influence  may  be  classed  as  an  in- 
stinct.     The  power  of  balancing  the  system,  seems  to  be 
rather  dependent  on  overcoming  fear  and  trusting  to  the 
power  which  has  been  spoken  of,  and  on  strengthening  the 
muscles,  than  on  perfecting  the  action  of  the  voluntary  in- 
fluence. 

219.  Habit  has  however  its  effect,  either  on  the  produc- 
tion of  the  influence  or  on  its  exercise ;  for  a  disease  having 
existed,  its  symptoms  continue  after  it  has  disappeared  ;    as 
frequently  a  child  cured  of  chorea  continues  to  twitch,  and 
other  illustrations  might  be  given.     In  such  cases  it  is  neces- 
sary to  produce  a  powerful  influence  on  the  mind ;  and  many 
wonderful  cures  effected  by  pills  of  bread  or  something  not 
as  harmless,  found  in  the  recommendations  with  which  quacks 
gloss  their  advertisements,  may  be  accounted  for  in  this  way. 

220.  The  action  of  the  muscles  is  facilitated  by  cellular 
substance,  bursse,  and  fat. 

221.  Cellular  substance  (Fig.  33)  has  been  spoken  of  as 
found  between  the  muscular  fibres  and  fasciculi ;    it  is  also 
found  between  the  muscles,  between  those  and  the  skin,  and 
between  many  other  parts  of  the  body. 

222.  Sometimes  it  is  condensed  so  as  to  form  a  thick 
fascia,  but  usually  it  has  the  appearance  exhibited  between 
the  muscles,  and  which  its  name  indicates ;  viz.,  it  is  formed 
of  very  delicate  membranes  intersecting  each  other  and  form- 
ing cells,  which  communicate  with  each  other  and  are  moist- 
ened upon  their  inner  surface,  by  a  fluid  very  similar  to  sy- 
novial,  but  called  serous  fluid.     From  the  fluid  it  forms,  the 
cellular  is  also  called  a  serous  membrane. 


TO  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP. 

Fig.  33. 


Fig.  33. — A  small  portion  of  cellular  substance  or  flesh,  stretched  so  as  to  show  it» 
cells. 

223.  This  fluid  is  continually  formed  and  removed,  as  is 
the  synovial  fluid,  and  like  it  sometimes  is  wanting  or  accu- 
mulates ;    in  this  last  case  producing  a  kind  of  dropsy  called 
anasarca,  for  which  sometimes  medicines,  sometimes  an  ope- 
ration called  tapping,  is  required.     The  result  of  this  shows 
the  communication  of  the  cells  with  each  other  ;  as  an  open- 
ing being  made  through  the  skin,  the  fluid  from  the  entire 
limb  is  drawn  off.    It  makes  its  way  from  one  cell  to  another. 

224.  The  rapidity  with  which  this  is  formed  is  shown  by 
the  swelling  of  the  feet,  which  will  sometimes  become  quite 
"  puffy  "  in  a  very  short  time,  and  again  be  reduced  as  quick- 
ly, though  this  is  partly  from  the  enlargement  and  diminution 
of  the  veins. 

225.  The  cellular  substance  is  seen  and  understood  by  the 
butcher  who  thrusts  a  tube  into  a  piece  of  meat  and  blows  the 
air  into  its  cells,  for  the  purpose  of  giving  it  a  better  appear- 
ance.    The  French,  for  a  disease  of  the  joints  of  horses,  pass 
a  tube  through  the  skin  and  blow  the  air  into  the  cellular  sub- 
stance of  the  entire  body.*    When  accident  sometimes  injures 

*  One  physiologist  proposed  to  inflate  the  cellular  substance  of  the 
body  with  hydrogen  gas,  that  its  buoyancy  might  enable  a  man  to  fly. 
A  somewhat  "  flighty  "  idea. 


SEC.  2.]  MUSCLES,  TENDONS,  ETC.  71 

the  side  of  the  chest  and  lung,  the  air  which  we  inhale  finds 
its  way  into  the  cellular  substance  and  the  whole  body  is 
inflated. 

226.  Its  nature  and  position  is  such  that  it  is  admirable 
as  a  "  packing,"  and  allows  the  muscles  to  move  over  each 
other  with  the  slightest  friction. 

227.  The  bursae  are  bags,  internally  moistened  with  a 
fluid  continually  formed  and  removed,  which  is  sometimes  defi- 
cient, sometimes  superabundant.     In  the  first  place,  inflam- 
mation is  soon  produced ;  in  the  last,  a  "  weeping  sinew  "  is 
the  result,  and  weakness  of  the  part  is  soon  complained  of. 
It  should  not  be  neglected  as  usual,  as  the  remedy  is  simple 
and  can  be  applied  by  any  physician,  though  it  may  require 
repetition  when  done  in  the  best  way.     Or  a  person  may  him- 
self lay  the  part  affected,  the  wrist  for  instance,  on  his  knee, 
and  strike  the  bursse  with  the  back  of  a  firm,  heavy  book,  with 
such  force  as  to  break  the  bag  and  allow  the  fluid  to  pass  out. 
This  is  usually  sufficient,  but  if  the  sides  of  the  bag  do  not 
from  inflammation  unite,  but  again  distend  with  fluid,  the  same 
operation  is  to  be  repeated.     Some  prefer  to  pierce  the  bursae 
and  inject  some  irritating  substance.      Had  I  one,  I  should 
have  it  treated  in  this  manner. 

228.  Being  placed  where  there  is  liability  to  friction,  their 
use  is  indicated.     A  large  one  is  found  at  the  elbow,  beneath 
the  skin ;    several  are  found  at  the  wrist ;    one,  of  an  hour- 
glass shape,  is  seen  by  pressing  upon  the  edge  of  the  palm 
of  the  hand,  as  the  fluid  from  the  front  part  is  pressed  back, 
and  can  be  readily  felt. 

229.  To  the  muscles  fat  serves  as  a  packing,  and  to  keep 
them  warm  when  deposited  between  the  skin  and  muscles  ;  in 
which  position  it  also  relieves  from  the  rigid  appearance  which 
the  contracted  muscles  would  otherwise  present.      Its  other 
uses  will  be  spoken  of  hereafter. 


72  ORGANS  OP  VOLUNTARY  MOTION.  [CHAP.  I. 


SECTION  3. — The  Brain  and  Nerves. 

230.  The  functions  of  the  nervous  system  are  numerous, 
but  in  this  section  will  be  considered  only  in  relation  to  mus- 
cular action. 

231.  In  this  respect,  the  office  of  the  nervous  system  is 
to  produce  nervous  influence ;   to  transmit  this  to  specific 
parts,  and  to  cause  it  to  act  upon  them. 

232.  The  places  where  it  is  produced  are  called  nervous 
centres ;    the  nerves  are  the  means  of  transmission,  and  the 
extremities  of  the  nerves,  or  an  unknown  apparatus  at  the 
extremities,  are  the  means  by  which  the  nervous  influence 
immediately  acts  upon  the  muscular  substance. 

233.  First)  The  Nerves  :    These  are  white  pulpy  cords, 
reaching  from  the  brain  and  spinal  cord  to  every  muscle  of 
the   body   (Fig.  34).      If  minutely  examined,  every  nerve 
is  found  to  be  composed,  like  a  skein  of  silk,  of  threads,  each 
of  which  might  with  propriety  be  called  a  nerve,  but  is  usu- 
ally called  a  nervous  filament. 

234.  Each  filament  is  composed  of  a  sheath,  filled  with 
a  pulp  or  jelly-like  substance.     Two  or  more  filaments,  situ- 
ated  by  the  side  of  each  other  and  covered  with  a  general 
sheath,  constitute  a  nerve,  which  is,  of  course,  larger  or 
smaller,  as  it  is  composed  of  many  or  few  filaments.      The 
filaments  are  extremely  minute,  being  finer  than  the  finest 
thread  of  the  spider. 

235.  As  the  destination  of  the  filaments  of  any  part  is 
the  same,  they  converge  towards  each  other,  forming  the 
smaller  nerves  j  which  converging  in  the  same  manner,  unite 
to  form  the  larger  ones.      Thus  are  formed  what  are  called 
branches  and  trunks.      These  are  not,  however,  like  those 
of  a  tree  or  stream,  blended,  or  properly  speaking,  united, 
but  in  this  wise :    if  ten  branches  be  composed  of  ten  fila- 


SEC,  3.] 


THE  BRAIN  AND  NERVES, 
Fig.  34. 


78 


Fig.  34.— In  the  upper  part  of  the  head  is  seen  the  large  brain.  In  the  lowerandbaek 
part,  the  small  brain  is  represented.     Below  this,  is  seen  the  commencement  of  the 


74  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

ments  each,  the  trunk  will  contain  one  hundred  in  its  entire 
length,  or  till  it  receive  additions  from  other  branches,  which 
will  increase  its  number. 

236.  The  general  neurilema,  or  nerve-sheath,  envelopes 
the  filaments  of  the  trunk  and  branches,  as  the  bark  of  a  leaf- 
less tree  incloses  the  wood.      An  inflammation  of  this  sheath 
or  membrane,  is  supposed  by  some  to  be  the  disease,  neural- 
gia ;  but  it  is  probable,  or  even  certain,  that  other  conditions 
also  produce  that  painful  complaint. 

237.  In  the  course  of  certain  nerves  are  found,  what  are 
called   plexuses  and  anastomoses  (Fig.  35).      The  lettered 
extremities  represent  the  nerves  coming  from  the  neck  re- 
gion of  the  spinal  cord  (Fig.  34).      In  the  plexus,  it  will  be 
seen  that  filaments  from  the  various  nerves  pass  across  each 
other,  and  unite  with  those  from  a  different  nerve.      The 
figured  extremities  of  the  plexus  are  therefore  composed  of 
filaments  from  each  of  the  lettered  extremities.      An  anasto- 
mosis is  a  small  plexus,  and  not,  as  its  name  signifies,  pro- 
duced by  a  genuine  uniting  of  the  nerves,  or  rather  an  open- 
ing of  the  nerves  into  each  other.      At  either  of  these,  the 
direction  of  the  filaments  is  merely  changed,  and  each  one 
can  be  traced  through  the  plexus  or  anastomosis.     The  object 
of  such  an  arrangement  seems  to  be,  to  allow  a  certain  de- 
gree of  influence  to  act  upon  any  part,  by  uninjured  branches, 
if  a  nerve  be  accidentally  severed,  and  to  allow  the  influence 
to  act   simultaneously   upon  different   and   perhaps   distant 
parts,  the  harmonious  action  of  which  is  required  in  accom- 
plishing any  object. 

238.  That  the  nerves  are  the  means  of  transmitting  the 
nervous  influence,  is  proved  by  the  effects  of  sections  and 

spinal  cord,  enlarged  between  the  shoulders  and  in  the  loins.  From  this,  the  nerves 
are  observed  extending  from  either  side  in  pairs,  the  large  ones,  in  the  region  of  the 
thighs  called  the  sciatic,  passing  down  the  lower  extremities,  being  especiallv  worthy 
of  notice.  In  the  loins  and  vicinity  of  the  shoulders,  the  nerves  are  observed  sending 
branches  to  each  other,  thus  forming  a  plexus.  As  the  nerves  unite  to  form  the  cord, 
it  is  also  observed  that  their  course  is  very  much  inclined  vipward  in  the  lower  part  of 
the  back,  and  scarcely  at  all  in  the  neck. 


SEC.  3.]  THE  BRAIN  AND  NERVES.  76 

Fig.  35. 


Fig.  3o.— This  represents  a  plexus,  and  the  fact  that  the  nerves  do  not  strictly  unite 
with  each  other,  but  that  the  filaments  of  one  pass  to  be  inclosed  in  the  sheath  of  an- 
other, their  course  and  neighbors  merely,  being  changed. 

compression  of  nerves.  Experimental  sections  can  be  made 
in  animals,  and  accident  affords  opportunity  of  observing  the 
effects  of  section  of  human  nerves.  A  lady  in  Concord,  by 
falling  upon  a  piece  of  glass,  cut  her  elbow  across  what  is 
commonly  called  the  "  funny  "  or  "  crazy  bone,"  by  which 
a  section  was  made  of  the  nerve  which  transmits  influence  to 
the  muscles  acting  upon  the  little  finger.  She  could  no 
longer  open  it.  If  a  divided  nerve  unite,  as  it  usually  will, 
in  a  longer  or  shorter  time,  control  over  the  muscles  is  again 
restored.  A  section  of  any  trunk  exhibits  an  effect  upon 
all  the  muscles  receiving  its  branches. 

239.  The  effect  of  compression,  is  exhibited  when  we 
strike  the  "  funny  bone  "  against  the  sharp  corner  of  any 
piece  of  furniture.     The  little  finger  and  side  of  the  hand  are 
not  only  numb  in  feeling,  but  are  for  an  instant  immovable 
by  any  influence  we  may  try  to  exert  upon  their  appropriate 
muscles ;    but  as  soon  as  the  nerve  has  recovered  from  the 
effects  of  compression,  the  muscles  are  again  subject  to  our 
command. 

240.  A  large  nerve,  "  great  sciatic  "  (Fig.  34),  in  a  part 
of  its  course,  is  so  situated  that  it  is  sometimes  compressed 
between  an  unpleasant  seat  and  the  hip  bones.      The  effect 
produced  is  described  by  saying  "  the  foot  is  asleep."*     The 

*  This  state  of  things  is  not  produced  by  a  stoppage  of  the  circula- 
tion of  the  blood,  as  is  usually  supposed, 


76  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

influence   being  to  a  great  degree  cut  off  from  the  muscles 
of  the  foot  and  leg,  they  are  moved  with  difficulty,  if  at  all. 

241.  A  tumor  sometimes  grows  in  such  a  situation  as  to 
compress  a  nerve,  exhibiting  peculiar  effects  in  the  parts 
where  the  filaments  of  a  nerve  terminate.      Removal  of  the 
tumor  removes  its  effects.      Disease  of  a  nerve,  and  some- 
times  disease  of  the  part  through  which  the  nerve  passes, 
produce  like  effects,  exhibited  in  the  parts  where  the  nerve 
terminates. 

242.  When,  from  any  cause,  control  over  the  muscles  is 
lost,  they  are  said  to  be  paralyzed,  when  perhaps  they  are 
perfect,  and  ready  to  act,  if  the  influence  were  only  exerted 
upon  them.      Hence,  sometimes  rubbing  the  muscles,  &c., 
will  produce  a  favorable,  and  sometimes  no  effect,  the  cause 
of  their  inaction  being  far  distant  from  them. 

243.  How  the  nervous  influence  is  transmitted  through 
the  nerve,  what  effect  it  produces  on  the  nerve,  or  the  nerve 
on  it,  or  whether  the  nerve  rapidly  undergoes  changes  while 
fulfilling  its  duties,  is  not  known.     Our  present  ignorance  of 
the  intrinsic  nature  of  the  nervous  influence  and  its  mode  of 
action,  precludes  us  from  arguing  very  successfully,  as  to 
what  is  or  ought  to  be  the  condition  and  manner  of  acting 
of  the  nerves.      The  nerves  do  not  seem  to  undergo  changes 
very  rapidly,  as  they  receive  comparatively  but  a  small  sup- 
ply of  blood.      Hence  they  are  seldom  attacked  by  the  in- 
ffammation  which  exists  in  parts  which  they  traverse.     This 
is  another  remarkable  instance  of  the  admirable  arrangement 
which  pervades  the  whole  system. 

244.  Each  nervous  filament  has  the  property  of  isolating, 
as  the  expression  is,  the  influence  transmitted  through  it ; 
that  is,  through  any  filament  of  a  nervous  trunk  an  influence 
can  be  caused  to  act  upon  its  appropriate  muscle  or  part  of  a 
muscle,  without  any  influence  being  communicated  to  its 
nearest  neighbor. 


SEC.  3.]  THE  BRAIN  AND  NERVES.  77 

245.  This  exhibits  a  marked  difference  between  the  ner- 
vous influence  and  all  those  things  to  which  it  has  sometimes 
been  compared,  and  with  which  some  have  thought  it  iden- 
tical, viz.,   electricity,  galvanism,  magnetism,  &c.      These 
will  pass  from  one  filament  to  all  the  rest  in  the  same  nerve ; 
and  if  applied  to  a  trunk,  will  exhibit  effects  in  the  muscles 
of  all  its  branches. 

246.  There  seems  to  be  no  proof  that  the  filaments  of  a 
nerve  increase  in  number  or  size  by  use.      Nor  does  there 
seem  to  be  any  necessity  for  such  increase.      For  aught  we 
know,  the  most  delicate  filament  is  sufficient  for  the  transmis- 
sion of  ten  times  the  nervous  influence,  if  such  an  expression 
may  be  allowed,  as  is  ever  transmitted,  when  the  most  pow- 
erful exertions  are  made.      Observe  the  almost  superhuman 
force   exhibited    in   certain   diseases.      Whether   the  influ- 
ence can  be  transmitted  with  any  more  facility  or  rapidity, 
when  it  is  done  frequently,  is  not  known.      Action  of  the 
muscle  is  produced  with  more  precision,  alacrity,  and  grace- 
fulness, when  frequently  and  properly  repeated  ;  whether  this 
depend  at  all  upon  an  improved  condition  of  the  nerve,  is 
conjectural. 

247.  As,  however,  the  development  and  preservation  of 
the  nerves  must  depend  upon  an  adequate  supply  of  blood, 
it  is  presumable  that  rubbing  and  general  exercise,  which 
increases  the  flow  of  blood  through  every  part,  would  be 
highly  beneficial  to  the  nerves.      This  would  be  especially 
the  case,  when,  from  disease,  the  action  of  any  part  is  torpid  ; 
for  then  the  restoration  of  the  nerves  thereof,  must  be  very 
much  hastened  by   accelerating  the  flow  of  blood,  by  fre- 
quent and  brisk  rubbing,  particularly  as  the  muscles  of  the 
part  are  incapable  of  effecting  much  by  exercise.      It  is  a 
general  rule,  that  any  part  which  receives  but  little  blood  in 
health,  is  very  tardy  in  recovery  when  diseased,  especially 
if  the  disease  be  of  a  low  character.      If,  however,  the  dis- 


78  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

ease  be  of  an  active  character,  and  acute  inflammation  exist, 
so  that  rubbing  produces  acute  pain,  it  should  be  dispensed 
with. 

248.  Second)    The   terminations   of   the   nerves.      The 
nerves  are  so  exceedingly  delicate,  when  they  reach  the 
muscles  influenced  through  them,  that  the  statements  of  au- 
thors in  respect  to  their  mode  of  terminating  are  very  dis- 
crepant.     Some  suppose  that  the  nerves  arrive  at  a  simple 
termination.      Others  suppose  that  the  nerves  terminate  in 
loops,  by  which  arrangement  they  suppose  they  can  account 
for  effects  seen.      Others  again  suppose  that  there  is  some 
peculiar  arrangement  at  the  extremities  of  the  nerves,  by 
virtue  of  which  the  influence  derived  through  the  nerve  acts 
upon  the  muscle.      Some  suppose  that  a  substance  of  a  pe- 
culiar character  may  be  discovered  at  the  extremities  of  the 
nerves    in  the  muscles.      Others,  and  I  believe  correctly, 
think  that  when  the  filaments  reach  the  muscles  in  which 
they  terminate,  they  are  connected  with   genuine  branches, 
which  are  indeed  parts  of  them,  in  such  wise  that  the  influ- 
ence acting  through  a  filament,  acts  through  all  these  minute 
twigs,  which  increase  and  diminish  in  number  with  the  in- 
crease or  diminution  of  the  muscle. 

249.  There  must  be  something  peculiar  in  the  extremity 
of  the  nerve,  and  different  from  its  remaining  parts  ;    as  the 
muscles  traversed  by  a  nerve  will  remain  entirely  inactive, 
while  those  at  the  extremity  are  violently  contracted.      The 
influence  must  be  caused  to  act  through  a  certain  distance  from 
the  extremities,  as  these  do  not  touch  each  other ;  while,  on  the 
other  hand,  the  sphere  of  influence  must  be  very  limited,  as 
one  fasciculus  of  a  muscle  may  be  brought  into  action,  while 
others  in  contact  with  it  are  uninfluenced.     The  darkness  in 
which  we  thus  sometimes  grope,  should  not  discourage  the 
student,  nor  dishearten  the  confidence  of  the  reader  ;  but  en- 
courage the  first  to  greater  diligence  in  investigating  a  sub- 


SEC.  3.]  THE  BRAIN  AND  NERVES.  79 

ject  so  interesting,  the  unfolding  of  which  will  prove  so  valu- 
able to  mankind,  and  enrol  his  name  among  those  of  whom 
all  men  speak  with  love  and  reverence ;  and  assure  the  last, 
that  much  of  the  disease  which  the  skill  of  the  physician 
cannot  prevent  or  cure,  is  owing,  not  to  the  inefficiency  of 
science,  but  to  our  ignorance,  which  difficulty,  we  hope  some 
day  will  overcome. 

250.  Third,  The  nervous  centres  :    These  will  be  found 
in  the  brain  and  spinal  cord,  as  is  proved  by  section  and  com- 
pression of  nerves,  reaching  from  those  parts  to  the  muscles, 
as  before  illustrated,  and  by  the  effects  of  disease  of  the  brain 
and  cord. 

251.  In  the  first  place, — the   cord    and  its  protections. 
The  back-bone,  in  which  the  cord  is  situated,  is  its  chief  pro- 
tection.    This  is  composed  of  twenty- four  bones,  called  ver- 
tebrae, resting  on  the  "  sacrum,"  or  sacred  bone — so  called 
from  its  being  offered  by  some  ancient  nations  in  sacrifice. 

252.  These  bones  vary  in  size  and  thickness,  in  different 
parts  of  the  back ;    in  the  loins  they  are  very  large  and 
strong,  presenting  a  great  extent  of  surface  for  the  attach- 
ment of  parts.     The  front  part  of  the  bone  (Fig.  36)  is  call- 
ed its  body.      This  is  very  conspicuous  in  the  loins,  growing 
less  and  less  so,  till  we  arrive  at  the  skull.      Between  each 
two  of  these,  except  the  two  upper  ones  of  the  neck,  is  found 
a  cushion  of  elastic  substance,  called  fibro-cartilage.      This 
is  very  thick  in  the  loins,  quite  thin  in  the  chest,  and  inter- 
mediate in  the  neck,  according  to  the  necessities  of  the  part 
where  it  is  found. 

253.  The  hole  (Fig.  36)  assists  in  forming  a  canal  called 
the  rachidien,  which  exists  in  the  entire  length  of  the  spinal 
column.     The  diameter  of  the  hole  varies  in  different  bones, 
as  may  be  seen  by  examining  Fig.  37.      The  hole  in  each 
vertebrae  is  greater  at  its  upper  and  lower  edge  than  in  the 
middle,  as  in  Fig.  38.     By  this  arrangement,  when  the  back 


80  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  36. 


Fig.  36.— A  vertebrae  representing  the  body,  the  hole,  the  lateral  (side)  processes, 
and  the  spinous  (spine-like)  or  posterior  (back)  process. 


is  curved,  the  contents  of  the  canal  are  not  injured  by  pres- 
sure upon  the  sharp  edges  of  the  vertebral  hole,  as  would  be 
the  case  if  the  hole  had  been  as  represented  by  the  dotted 
lines  (Fig.  38). 

254.  The    projection  at  the  back  of  bone,  Fig.  36,  and 
which  is  so  distinctly  felt  in  the  back  of  any  person,  is  called 
the  spinous  or  spine-like  process.      A  remarkable  difference 
is  observable  in  the  arrangement  of  this,  upon  different  bones. 
In  the  loins  it  projects  directly  backward  (Fig.  40) ;    and 
when  the  back  is  erect,  there  is  quite  a  space  between  the 
processes  of  adjoining  bones.      In  the  chest,  the  process  in- 
clines downward  very  much,  as  seen  by  comparing  Figs.  39 
and  40 ;    and  when  the  back  is  erect,  they  almost  or  quite 
touch  the  bone  below.      In  the  neck,  the  inclination  is  less 
and  less,  as  is  also  the  size,  till  we  ascend  to  the  two  upper 
ones,  which  are  like  those  of  the  loins,  but  not  as  large,  of 
course. 

255.  Two  objects  are  gained  by  this  admirable  arrange- 
ment.     Great  extent  of  motion,  forward  and  backward,  is 
desirable,  in  the  region  of  the  loins  and  upper  part  of  the 


Fig.  37. 


ORGANS  OF  VOLUNTAKY  MOTION.  [CHAP.  I. 

Fig.  38. 


Pig.  38. — Is  an  ideal  representation  of  two  bones  with  their  intervening  cartilage  (2) 
of  the  back  ;  1, 1,  the  bodies  of  the  bone,  through  which  a  section  has  been  made  ;  3, 3, 
are  the  posterior  (back)  processes  of  the  same ;"  4,  4,  is  the  canal  in  the  back-bone,  the 
surfaces  of  the  bones  upon  either  side  being  full  in  the  middle  (opposite  4,  4),  and  re- 
ceding above  and  below.  If  the  surfaces  had  been  in  the  direction  of  the  doited  lines, 
the  canal  would  have  been  of  the  same  size  at  the  top,  middle,  and  bottom  of  the  bone ; 
bat  now  there  is  opportunity  for  the  bones  to  bend  without  causing  any  angles  in  the 
canal,  or  lessening  it,  prejudicially  to  the  cord. 

neck ;  while  a  forward  movement  of  the  vertebrae  of  the 
chest  should  be  very  limited,  and  is  made  so  by  the  position 
of  the  ribs ;  and  backward  motion,  which  would  be  still  more 
deleterious,  is  properly  restricted,  by  the  inclination  of  the 
processes  of  the  dorsal  vertebrae.  In  the  next  place,  the 
muscles  attached  to  the  spines,  which  are  not  inclined,  have, 
as  will  be  seen,  a  greater  lever  power,  which  is  required  for 
readily  producing  the  desirable  motions.  The  combination 
of  great  size,  strength,  and  extent  of  surface ;  the  action  of 
the  cushions,  thick  and  elastic ;  the  strong,  perpendicular 
spines  ;  and  the  conspicuous  and  proper  enlargement  of  the 


Fig.  37. — Represents  a  front  view  of  the  brain  raised  up,  and  the  spinal  cord, — the 
bodies  of  the  vertebrae  being  removed.  The  black  spots  represent  sections  of  the  bone, 
between  which  the  nerves  are  seen  passing  out.  The  greater  distance  of  the  spots 
from  each  other  at  different  parts  of  the  back,  and  the  curve  of  the  bone  on  the  face 
toward  the  cord,  exhibit  the  facility  with  which  the  back  may  be  bent  and  the  cord  not 
injured.  At  the  upper  part  of  the  cord,  an  enlargement  represents  the  medulla  oblon- 
gata  (oblongated  marrow)  ;  immediately  above  this,  the  cross  lines  show  the  pons  Va- 
riolii  (bridge  of  Variolius),  as  he  suggested  that  the  fibres  of  which  it  is  composed  might, 
like  bridges,  serve  to  connect  certain  parts  of  the  two  halves  of  the  brain.  Above  thia 
is  seen  the  crossing  of  the  nerves  of  sight,  called  the  optic  commissure,  and  above  this, 
the  deep  fissure,  found  between  the  two  halves  of  the  brain.  The  continuous  lines  upon 
each  side  of  the  centre,  extending  from  the  upper  part  of  the  neck  to  the  sacrum,  in 
front  of  which  they  are  united  by  "cross  lines,  represent  the  situation  of  what  are  called 
the  sympathetic  nerves,  upon  the  ribs  upon  each  side  of  the  back-bone ;  in  their 
course,  several  enlargements  called  ganglions  are  seen,  and  they  are  represented  as 
connected  by  small  branches,  with  the  nerves  coming  out  from  the  spinal  cord. 


SEC.  3.]  THE  BRAIN  AND  NEftVES.  83 

Fig.  39.  Fig.  40. 


Fig.  39. — Represents  one  of  the  vertebrae  of  the  back  (a  dorsal  vertebrae ).  2,  The 
body  of  the  bona.  3,  The  spinous  process  very  much  inclined  down.  7, 7,  The  notches 
through  which  the  nerves  come  out. 

Fig.  40. — Represents  a  lumbar  (loins)  vertebras.  2,  The  body  of  the  bone.  3,  The 
epinous  process  not  inclined.  7,  7,  Notches  for  the  passage  of  nerves. 

central  hole  or  foramen  at  its  upper  and  lower  edges,  in  case 
of  the  lumbar  (or  loins)  vertebree,  is  only  one  among  a  hun- 
dred instances  of  the  perfection  which  reigns  through  the 
whole  system.  Is  not  such  beauty  and  perfection  decided 
proof  that  disease  and  premature  death  is  not  in  accordance 
with  the  intentions  of  Nature  ? 

256.  The  prominences  at  the  sides  of  the  bone  (Fig.  36) 
are  called  the  lateral  or  side  processes.      They  serve  for  the 
attachment  of  muscles,  and  in  the  region  of  the  chest,  afford 
support  to  the  ribs. 

257.  Between  each  two  vertebrae,  at  the  sides,  a  hole  is 
found,  called  the  intervertebral  foramen,  or  between  the  ver- 
tebrae hole       This  is  partly  excavated  from  the  lower  bone 
of  the  two,  but  mostly  from  the  upper.     Through  these  holes 
the  appropriate  nerves  find   a   passage   into  the  rachidien 
canal. 

258.  The  second  protection  is  found  in  what  is  called  the 
dura  mater  (Fig.  41).     This  is  a  dense  membrane,  about  one- 
sixteenth  of  an  inch  thick,  which  lines  the  rachidien  canal, 
being  connected  with  the  vertebras  at  several  points,  but  not 
very  closely.     Between  it  and  the  bones  there  is  a  portion  of 


84  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

oily  or  fatty  substance,  (during  life  it  is  between  oil  and  lard 
in  its  consistence,)  situated  in  its  appropriate  cells.  This 
facilitates  the  movements  of  the  internal  cord. 


Fig.  41. 


Fig.  41.— Represents  the  bodies  (a,  a,  a)  of  three  bones  of  the  back,  broken  from 
the  back  parts  (c,  c,  c),  which  are  drawn  away  a  little  distance,  that  a  view  may  be 
given  of  a  perpendicular  section  of  the  spinal  cord  (5),  and  the  parts  (1,  2,  2,  3,  4)  be- 
tween the  cord  and  the  inner  surface  of  the  bones.  1,  Dura  mater.  2,  2,  The  two  lay- 
ers of  the  arachnoid  represented  as  reflected  at  6.  3,  The  coarse  cellular  substance 
occupying  what  is  called  the  sub  (under>arachnoid  space.  45  The  pia  mater. 

259.  Another  protection  is  found  in  the  arachnoid   or 
spider's- web  membrane.     As  its  name  indicates,  it  is  exceed- 
ingly de-licate.     It  lines  and  closely  adheres  to  the  dura  ma- 
ter  by  one  surface,  at  first  appearing  like  a  part  of  it,  and  is . 
reflected,  as  the  expression  is,  so  as  to  form  another  tube  and 
cover  the  parts  within   it,  to  which  it  adheres.      The  two 
surfaces  which  are  toward  each  other  do  not  adhere,  but  are 
called  free,  and  are  moistened  by  a  fluid  called  serous,  exist- 
ing in  health  only  in  small  quantities,  as  it  is  formed  and  re- 
moved in  the  most  constant  ratio  by  the  action  of  the  mem- 
brane  itself. 

260,  The  side  of  the  more  internal  arachnoid,  toward  the 
cord  is  connected  with  a  cellular  substance,  existing  between 
this  membrane  and  the  one  which  directly  covers  the  cord. 
The  cells  of  this  being  filled  with  fluid,  distend  the  internal 


SEC.  3.]  THE  BRAIN  AND  NERVES.  85 

arachnoid,  and  keep  the  two  surfaces  of  the  two  arachnoids 
in  contact,  affording  admirable  protection  to  the  cord. 

261.  Still  another  protection  is  found  in  the  pia  mater, 
which  is  the  name  of  a  membrane  which  immediately  covers 
the  cord,  closely  adhering  to  it,  indeed  rather  compresses  it, 
as  when  the  membrane  is  cut,  the  cord  protrudes. 

262.  From  the  sides  of  the  pia  mater,  a  portion  called  a 
process  projects,  and  from  this  certain  points  reach  as  far  as 
the  dura  mater.      These  form  what  are  called  the  ligamenta 
dentata  (Fig.  42).     These  support  the  cord,  or  retain  it  in  a 
central  position,  allowing  it,  however,  a  certain  degree  of  mo- 
tion.     The  same  purpose  is  subserved  by  a  process,  as  it  is 
termed,  of  the  pia  mater,  which  is  attached  to  the  lowest 
point  of  the  rachidien  canal. 

Fig.  42. 


Fig.  42.—  A  represents  (3,  2)  a  horizontal  section  of  the  cord  and  pia  mater  covering 
it,  and  at  1, 1,  passing  to  the  lining  (4)  of  the  bony  canal.  1, 1,  are  called  the  ligamenta 
dentata,  one  of  which  is  represented  in  B;  which,  by  1,  represents  a  perpendicular 
section  of  the  cord ;  2,  2,  the  pia  mater ;  3,  the  ligamentum  of  one  side,  which  at  cer- 
tain places  extends  to  the  wall  in  the  form  of  points  or  tooth-like ;  hence  the  name 
deutata. 

263.  The  cord  extends  from  the  skull  to  the  lumbar  ver- 
tebree,  when  its  large  divisions  form  the  "  cauda  equina,"  or 
horse-tail  (Fig.  34).  The  position  of  its  lower  extremity 
varies  with  the  posture  of  the  back.  In  a  stooping  postura 
it  is  not  as  low  as  when  the  attitude  is  erect.  The  cord  ii 


86  ORGANS  OF  VOLUNTARY  MOTION.  [cHAP.  I, 

susceptible  of  being  lengthened,  and  is  stretched  when  the 
back  is  curved.  Externally  viewed,  the  cord  is  a  white 
pulpy  substance,  so  much  resembling  the  marrow  of  the 
bones  as  frequently  to  be  called  the  spinal  marrow.  It  is 
not,  however,  a  fatty  substance,  as  the  marrow,  but  is  mostly 
composed  of  nervous  fibres,  like  the  nerves,  many  of  which 
are  indeed  the  same. 

264.  If  a  section  of  the  back  be  made,  as  in  Fig.  37,  the 
nerves  will  be  seen  entering  through  the  intervertebral  fora- 
mina and  the  membranes  of  the  rachidien  canal,  to  unite 
with  or  form  the  cord.     At  the  lower  part,  as  in  Fig.  37,  or 
Fig.  34,  the  filaments  of  the  nerve  are  seen  inclining  very 
much  upward,  after  they  enter  the  canal ;    but  the  upper 
nerves  unite  more  horizontally  with  the  cord ;    indeed,  the 
upper  pair  rather  incline  downward. 

265.  If  a  transverse  section  of  the  cord  be  made,  it  will 
be  seen  (Fig.  43)  to  be  composed  of  two  halves,  sometimes 
called  two  cords,  united  by  a  narrow  band  of  white  fibres, 
called  a  commissure.     This  accounts  for  the  deep  front  and 
shallow  posterior,  dividing  grooves  seen  in  the  entire  length 
of  the  cord. 

Fig.  43. 


Fig.  43. — Represents  a  cross,  transverse,  or  horizontal  section  of  the  spinal  cord,  th« 
dark  half-moon  shaped  spots  representing  the  gray  substance. 

266.  Each  half  is  composed  internally  of  a  gray  sub- 
stance,  differing  in  its  arrangement  in  different  parts  of  the 
cord  ;  its  general  appearance  being  that  of  a  half-moon,  with 
its  convex  side  toward  the  other  half,  one  horn  reaching  quite 
to  the  surface,  and  dividing  each  half  into  the  smaller  back 


SEC.  3.]  THE  BRAIN  AND  NERVES.  87 

or  posterior,  and  larger  front  or  anterior  columns,  as  they  are 
called. 

267.  The  gray  has  hardly  as  much  consistence  as  the 
white  substance.     In  great  part,  it  seems  to  be  composed  of  a 
granular  substance,  most  nearly  described  by  the  word  jelly ; 
while  the  white  substance  appears  to  be  mostly  fibrous. 

268.  The  use  of  this  gray  nervous  substance,  whether 
found  here  or  elsewhere,  is  not  known.      But  as  it  is  easy  to 
form  conjectures,  this  has  been  done.      Some  suppose  that  it 
is  the  generator  of  the  nervous  influence,  distributed  through 
the  white  fibres,  and  consider  that  there  is  a  nervous  centre 
wherever  this  gray  substance  is  found,  and  speak  of  collections 
of  it,  as  brains.     To  confess  ignorance  is,  however,  far  more 
honorable  than  to  support  a  fallacy ;  beside  that,  it  deceives 
ourselves ;  for  truth  is  so  lucid  and  necessarily  supported  by 
such  strong  arguments,  it  is  at  once  recognized  by  the  mind 
unprejudiced  by  adherence  to  invented  theories. 

269.  Some  have  supposed  the  white  portions  of  the  cord 
are  composed  of  the  nerves,  which  enter  the  canal  to  pass  up 
to  the  brain.     In  this  case,  the  cord  would  be  a  very  simple 
thing  to  consider,  viz.  a  great  nerve — the  grand  trunk  of  the 
body.      But  then,  why  such  care  in  the  arrangement  of  its 
protections  ?     Why  the  gray  substance  ?     Why  the  enlarge- 
ments of  the  cord  in  the  region  of  the  shoulders,  where  the 
nerves  of  the  upper  extremities  come  off;    or  in  the  lower 
part  of  the  cord,  where  the  nerves  of  the  lower  limbs  leava 
the  spinal  marrow  ? 

270.  The  best  testimony  and  examination  seem  to  prove 
that  a  portion  of  the  nervous  fibres  commence  at  or  in  the 
cord,  while  another  portion  forms  a  part  of  the  cord,  being 
continuous  from  the  brain  ;  while  it  is  not  impossible,  but  al- 
together probable,  that  nerves  commence  at  the  brain  and 
terminate  in  the  cord,  as  will  be  made  more  clear  hereafter. 

271.  In  fulfilling  one  of  its  duties,  the  cord  may  then  be 


88  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

considered  as  a  mere  nerve,  transmitting  influence  from  the 
brain.  In  fulfilling  another  duty,  it  may  be  considered  as  a 
nervous  centre,  or  as  a  congeries  of  nervous  centres,  where 
nervous  influence  is  produced,  and  from  which  it  is  transmit- 
ted to  the  muscles. 

272.  If  the  head  of  a  turtle  be  removed,  and  a  coal  of  fire 
placed  upon  his  back,  as  soon  as  the  heat  affects  the  cord,  with 
harmonized  action  the  legs  scramble  off  with  the  body  as 
fast  as  possible.      If,  however,  the  cord  be  destroyed,  by 
thrusting  a  wire  down  the  canal,  nothing  of  the  kind  takes 
place.      If  only  the  front  portions  of  the  cord  be  destroyed, 
the  motions  of  the  fore-paws  only  cease.     To  show  that  there 
are  several  centres  in  the  cord,  various  illustrations  might  be 
used  ;    but  space  cannot  be  allowed  to  what  may  ultimately 
prove  valueless. 

273.  In  addition  to  what  has  been  said,  it  may  be  well  to 
exhibit  in  brief  the  opinions  of  the  most  eminent.     Some  sup* 
pose  that  the  whole  nervous  system  is  continually  charged 
with  influence,  which  is  continually  passing  to  the  muscles 
in    a    certain    degree,    and    is    increased    when   desirable. 
Others  think  the  influence  is  produced  at  the  end  of  the 
nerves,  and  is  operated  in  some  way,  as  yet  incomprehen- 
sible, through  the  nerves ;  by  some  thought  to  be  accomplish- 
ed by  a  tremulous  movement  of  the  nervous  filament,  which 
nothing  has  proved  to  exist.      Others  think  that  a  change  is 
produced  in  the  nerve,  and  propagated  through  the  entire 
length  of  it ;  some  thinking  that  this  consists  in  a  mere  pro- 
pulsory  action  from  one  particle  to  another,  and  some,  that  a 
decided  change  is  produced  in  the  particles  forming  the  line 
of  action.     Most  suppose  that  an  entity  is  produced  at  the 
nervous  centres,  acting  by  certain,  its  own   laws,  through 
the  nerves,  with  the  quickness  of  lightning,  and  the  perfec- 
tion of  results  which  mark  the  works  of  the  Creator  only. 
Some  of  these  last  consider  that  the  influence  is  produced  in 


SEC.  3.]  THE  BRAIN  AND  NERVES.  89 

the  brain  only,  from  which  it  is  disseminated  ;  others,  that  it 
is  produced  in  the  cord  only,  from  which  it  passes  off*,  some- 
times under  the  action  of  the  brain,  sometimes  not.  Some 
think  there  is  but  one  grand  centre  in  the  cord ;  others  sup- 
pose there  are  several.  Some  again  think  that  both  the  brain 
and  cord  are  centres,  and  some  that  there  are  several  centres, 
either  in  the  brain  and  cord,  or  cord  and  brain,  or  in  both. 

274.  It  may  seem  strange  that  there  are  so  many  opinions 
upon  so  important  a  point,  but  the  opinions  are  not  more  di- 
verse than  the  facts  that  can  be  advanced  in  their  support ; 
and  no  theory  upon  this  subject  has  been  advocated,  which  is 
not  opposed  by  some  fact.      A  large  part,  however,  of  the 
suppositions  under  IF  273,  and  many  more  like  them,  are  evi- 
dently fanciful,  and  have  few  supporters.     There  is  also  one 
apology  to  be  made.     Scarcely  any  dependence  can  be  placed 
upon  analogy,  the  source  of  many  fallacious  arguments,  for 
all  animals  are  not  operated  upon  in  the  same  way  by  similar 
experiments ;  and  a  striking  difference  exists  between  effects 
upon  other  animals  and  man. 

275.  One  theory  is  however  worthy  of  more  distinct  no- 
tice.    Sir  Charles  Bell  supposed  he  had  proved  that  the  mid- 
dle portion  of  the  sides  of  the  upper  part  of  the  cord  were 
nervous  centres.     In  these  he  thought  the  influence  was  pro- 
duced which  acts  upon  the  respiratory  or  breathing  muscles, 
and  uncontrolled  by  the  brain.      My  own  opinion,  and  that 
of  most,  I  believe,  is  in  favor  of  the  theory ;  but  some  do  not 
regard  it  as  correct. 

276.  Diseases  of  the  spinal  cord  are  various  and  very 
perplexing  to  the  physician,   from  ignorance  of  the  nature 
of  the  nervous  influence,  its  mode  of  production  and  action, 
and  the  effects  which  its  production  will  have  upon  the  appa- 
ratus producing  or  transmitting  it. 

277.  Its  diseases  and  injuries  exhibit  paralysis,  convul- 
sions, cramps,  lockjaw,  shaking  palsy,  general  weakness  of 


90  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

the  muscles,  &c.  Some,  perhaps  all  of  these,  may  also  be 
exhibited  while  the  cord  is,  to  all  appearance,  in  a  healthy 
condition.  These  exhibitions  may  be  partial  or  general. 
One  muscle,  for  instance,  may  be  affected,  or  all  below  the 
injured  point,  or  only  the  muscles  of  one  side,  according  as  a 
few  filaments  of  the  cord,  the  whole  of  it,  or  the  half  is  af- 
fected. 

278.  One  of  the  most  simple  ways  of  ascertaining  the 
existence  of  certain  common  diseases  of  the  back-bone  or  its 
contents,  is  to  exert  pressure  along  its  extent,  when  pain  will 
be  felt  if  disease  exist.     In  case  it  does,  the  earliest  attention 
should  be  given,  and  the  most  assiduous  care  must  be  bestow, 
ed,  for  a  long  time,  and  in  many  cases  it  will  be  imperatively 
required.     A  person  of  real  science,  skill,  judgment,  and  in- 
dustrious patience  to  investigate  and  apply,  is  the  only  one 
who  can  afford  the  assistance  which  nature  requires,  and  even 
then  failure  must  be  expected. 

279.  To  prevent  the  recurrence  of  such  disease  is  worth 
trouble.      The  attention  may  therefore  be  drawn  to  one  evil 
very  generally  prevailing.      The  clothing  of  females  is  fre- 
quently so  arranged,  upon  the  lower  part  of  the  cord,  as  to 
preserve  a  temperature  too  elevated  for  its  health  ;  while  in 
cool  weather  the  upper  part  is  too  much  exposed  to  suffer 
from  a  low  temperature.     This  double  cause  acting  upon  the 
cord  at  the  same  time,  and  disturbing  the  circulation,  must 
prove  fruitful  of  the  worst  diseases. 

280.  That  rapid  changes  of  the  cord  are  produced  in  ful- 
filling its  duties,  can  only  be  inferred  from  the  large  quantity 
of  blood  which  circulates  through  the  vertebral  canal,  and 
the  liability  of  the  cord  and  its  appendages  to  inflammation. 
From  all  that  we  know  of  its  duties,  we  can  only  infer  that 
it  should  be  supplied  with  a  sufficient  quantity  of  good  blood. 

281.  In  the  second  place,  the  brain.     Its  outer  protection 
is  the  hairy  scalp  ;  beneath  this  is  found  a  layer  of  fatty  sub- 


SEC.  3.]  THE  BRAIN  AND  NERVES.  91 

stance  ;  then  cellular  substance,  muscles,  tendons,  &c.,  when 
we  reach  the  skull.  These  parts  serve  the  double  purpose 
of  preserving  the  temperature  of  the  head,  and  lessening  the 
effects  of  blows.  A  lady  of  my  acquaintance  was  once 
thrown  from  a  gig  against  the  sharp  edge  of  a  stone,  her 
bonnet  and  knob  of  hair  were  badly  cut ;  she  was  only 
stunned. 

282.  The  general  form  of  the  skull  has  been  demonstrat- 
ed (Arnott's  Physics)  to  be  the  best  possible  for  resisting  the 
effects  of  weight  or  blows  (Fig.  44).  The  figure  exhibits 
the  arch  found  at  the  summit  of  the  head ;  and  any  one  may 
learn  the  strength  of  the  arch,  by  observing  the  heavy  bur- 
dens the  arched  bridge  will  support  without  yielding ;  or  still 
better,  by  observing  his  own  head.  The  immense  blows  the 
negro's  skull  is  capable  of  resisting  is  proverbial. 

Fig.  44  (A). 


283.  Concussion,  or  a  severe  jarring  or  shaking,  seems  to 
injure  the  brain  more  than  cutting,  or  even  contusion. 
Hence  the  impropriety  of  striking  the  head,  even  in  the  way 
of  cuffing  the  ears.  To  prevent  concussion,  therefore,  the  ut- 
most care  has  been  taken.  The  skull  is  supported  upon  a 
doubly-curved  column,  composed  of  spongy  bones  and  inter- 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  1. 

Fig.  44  (B). 


placed  cartilage,  and  attached  in  such  a  lateral  manner  to  the 
hip-bones,  that  every  advantage  arising  from  a  combination 
of  the  most  perfect  springs  and  an  arrangement  for  the  dis- 
persion of  force,  exists  therein. 

284.  And  not  only  is  this  column  connected  laterally 
with  the  hip-bones — (if  the  thigh-bone  had  been  placed  di- 
rectly beneath  the  back-bone,  every  step  would  have  been 
shocking) — but  the  hip-bones  are  connected  laterally  with  the 
thigh-bones.      When  the  foot  strikes  the  ground,  these  form 
an  angle  with  the  lower  leg  bones,  which,  with  the  arrange- 
ment of  the  joints  of  the  ankle  and  foot,  produce  a  perfection 
which  leaves  nothing  to  be  wished. 

285.  The  skull  is  composed  of  three  layers ;    the  outer 
and  inner  are  called  tables,  the  intermediate  one  has  the 
name  of  diploe.     The  outer  table  being  tough,  is  broken  with 
difficulty,  while  the  diploe,  being  of  a  spongy  or  cellular  na- 
ture, deadens  the  jar  an  inflicted  blow  might  produce  in  the 
outer  table.     The  diploe  is  not  found  in  early  life,  when  the 
soft  state  of  the  bones  render  such  a  structure  unnecessary  ; 
but  as  the  bones  grow  brittle  with  advancing  age,  the  diploe 
not  only  makes  its  appearance,  but  increases  in  thickness  as 
the  case  requires. 


SEC.  3.]  THE  BRAIN  AND  NERVES.  93 

286.  The  inner  table  is  quite  brittle  and  altogether  averse 
to  vibrating  in  harmony  with  the  more  external  layers ;  and 
of  course  unharmonizing  vibrations  tend  to  neutralize  each 
other. 

287.  When  the  skull  is  removed,  the  first  internal  pro- 
tection is  found  in  the  dura  mater,  similar  to  that  lining  the 
spinal  canal,  indeed  one  is  a  continuation  of  the  other.     The 
dura  mater  of  the  skull,  however,  adheres  closely  to  it,  ex- 
cept when  it  dives  down,  as  a  separation  between  the  halves 
or  hemispheres  of  the  brain,  or  where  it  comes  forward  un- 
derneath the  back  part  of  the  upper  brain,  to  serve  as  a  shelf 
for  its  support. 

288.  In  the  first  position  it  is  called  the  falx,  from  its  sup- 
posed resemblance  to  an  ancient  sickle  (Fig.  45).     It  leaves 
the  skull  at  the  central  line,  and  passes  down  nearly  as  far 
as  the  division  of  the  brain  exists,  when  it  turns  back,  uniting 
with  the  first,  till  it  arrives  at  the  skull,  when  it  goes  on  to 
line  the  rest  of  the  skull.     The  falx  is  thus  composed  of  two 
thicknesses,  though  at  first  it  appears  only  one  thing. 

289.  On  the  back  part  of  the  head  is  a  ridge,  extending 
from  ear  to  ear.    Corresponding  to  this,  there  is  a  ridge  with- 
in the  skull,  from  which  the  dura  mater  comes  forward  so  far 
as  to  cover  the  cerebellum,  when  it  folds  back,  adhering  to 
itself,  so  to  speak,  to  the  ridge,  from  which  it  continues  down 
upon  the  inner  surface  of  the  skull. 

290.  The  dura  mater  is  every  where  lined  by  the  arach- 
noid membrane,  which  without  close  examination  seems  to  be 
a  part  of  it.     As  in  the  spinal  canal,  the  arachnoid  is  reflect- 
ed upon  the  more  internal  membrane  called  the  pia  mater. 
The  two  surfaces  toward  each  other  are  in  health  moistened 
by  a  glairy  fluid,  which  prevents  their  adhering.     Like  other 
serous  fluids,  it  is  in  health  removed  in  the  same  ratio  as  it  is 
formed.      As  there   is  no  fatty  substance  between  the  dura 
mater  and  its  bony  cashier,  as  there  is  in  the  spinal  canal,  so 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  45. 


Fig.  45. — Represents  the  fair  (3),  situated  between  the  two  halves  of  the  large  brain. 
Upon  the  under  and  upper  edge  are  seen  veins,  called  in  this  part  of  the  body  sinuses. 
2,  2,  Branches  opening  into  the  upper  sinus.  6,  8,  Branches  which  drain  the  lower 
portion  of  the  large  brain.  8,  Space  between  the  two  veins  into  which  the  great  sinua 
divides.  10, 11,  Two  large  veins  which  have  wound  round  to  the  side  of  the  bottom  ol 
the  skull. 


there  is  no  cellular  substance  between  the  arachnoid  and  all 
the  upper  parts  of  the  brain  ;  for  the  fatty  and  cellular  sub- 
stance are  alike  unnecessary.  But  at  the  bottom  of  the  skull 
the  cellular  substance  is  very  conspicuously  developed,  and 
supports  the  weight  of  the  brain  in  a  most  admirable  manner. 
The  fluid  contained  in  these  cells  communicates  with  that  in 
the  sub-arachnoid  space  about  the  pia  mater  of  the  cord,  and 
as  some  thin*,  affects  the  cord  favorably,  by  adding  its  weight 
to  the  fluid  of  the  canal.  Not  only  the  weight  of  the  fluid 
in  the  skull,  but  a  considerable  portion  of  the  weight  of  the 
brain,  must  be  counted.  Thus  it  is  seen  how  beautifully 
the  brain  is  placed,  resting  on  the  cellular  substance  and  fluid 
of  the  sub-arachnoid  spaces  ;  it  is  unconnected  above,  but  is 
allowed,  without  any  friction  or  danger,  a  certain  degree  of 
movement  in  the  skull,  at  the  free  surfaces  of  the  inner  and 
outer  arachnoid. 


SEC.  3.]  THE  BRAIN  AND  NERVES.  95 

291.  The  delicate  arachnoid  being  removed,  the  pia  ma- 
ter is  presented  to  view.      This  is  a  continuation  of  that  in 
the  canal,  where  it  is  quite  strong  and  protective,  as  is  re- 
quired for  the  support  of  the  cord  ;    but  at  the  upper  regions 
of  the  brain  it  becomes  exceedingly  delicate,  and  seems  com- 
posed almost  entirely  of  bloodvessels  of  surprising  minute- 
ness.    It  closely  envelopes  the  brain,  following  all  the  wind- 
ings of  its  surface,  and   is  much  greater  in  extent  than  the 
outer  membranes. 

292.  The  Brain.     What  is  usually  thus  called  is  com- 
posed of  two  parts,  or  as  they  are  termed,  the  large  brain  or 
cerebrum,  and  the  small   brain  or  cerebellum.      The  last  is 
found  below  the  tentorium,  in  the  lower  and  back  part  of  the 
head  ;  the  rest  of  the  head  is  occupied  by  the  cerebrum. 

293.  The  consistence  of  the  brains  may  be  compared  to 
jelly,  the  small  brain  being  a   little   more   firm   than   the 
large.     The  brains  therefore  flatten  as  soon  as  removed  from 
the  skull,  and  must  be  cut  with  a  very  sharp  knife  if  an  ex- 
amination be  desirable. 

294.  The  small  brain,  as  seen  in  Fig.  34,  is  comparative- 
ly smooth  on  its  external  surface,  and  divided,  as  seen  in  Fig. 
46,  into,  two  halves,  or  hemispheres,  by  a  shallow  groove, 
whicK  is  apparent  on  the  upper,  back,  and  under  surfaces. 
The  color  is  in  alternate  stripes  of_whjte_and  gray.     Its  size 
differs  in  different  persons,  being  usually  largerln  the  female 
than  in  the  male  of  the  human  species. 

295.  The  large  brain  is  composed  of  two  hemispheres, 
separated  by  a  deep  groove,  seen  at   1,  Fig.  37,  which  also 
passes  forward  from  the  back  part,  and  backward  from  the 
front  part  of  the  brain,  as  seen  in  Fig.  47.     In  this  groove 
the  falx  is  situated. 

296.  The  surface  of  the  cerebrum  is  very  uneven,  being 
much  like  that  of  a  peach-stone  (Fig.  48).     The  prominences 
are  called    convolutions ;    the    indentations,  anfractuosities. 


ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

Fig.  46. 


Fig.  46.— Upper  surface  of  the  small  brain. 

These  pass  quite  deeply  from  the  surface  in  many  places,  as 
seen  in  Fig.  47  ;  where  it  may  also  be  noticed,  that  convolu- 
tions and  anfractuosities  exist  in  the  groove  which  divides  the 
hemispheres.  They  will  also  be  found  at  the  base  of  the 
brain. 

297.  As  has   been  said,  the  pia  mater  follows   all  the 
windings  of  the  surface ;  while  the  arachnoid  lies  across,  so 
to  speak,  from  one  convolution  to  another. 

298.  The  color  of  the  external  portion  of  the  cerebrum 
is  very  nearly  like  that  of  the  ashes  of  "  red-ash  coal  " — a 
reddish  gray, — hence  called  the  cineritious  or  ash-like  part, 
the  gray  part,  and  is  also  called  the  cortical  or  bark  part, 
because  it  surrounds  the  inner  portion,  as  the  bark  of  a  tree 
surrounds  the  wood. 

299.  If  a  section  of  the  cerebrum  be  made,  Fig.  47,  this 
arrangement  will  be  conspicuous.     The  internal,  white  or 
medullary  substance,  is  convoluted  as   the  surface  of  the 
brain.     It  is  indeed  these  convolutions,  covered  by  the  gray 
substance,  which  produce  the  convolutions  of  the  surface 
The  thickness  of  the  covering  varies  from  a  sixteenth  to  a 
half  inch ;   differing  in  different  parts  of  the  same  brain, 
varying  still  more  in  different  brains  :  nor  are  its  thickest  or 
thinnest  parts  found  in  the  same  relative  portions  of  different 


SEC.  3.] 


THE  BRAIN  AND  NERVES. 


Fig.  47.— Represents  a  section  of  the  brain  on  a  level  with  the  bridge,  or  corpus 
callosum  (d,  e,  d) ;  a,  the  front ;  6,  the  back ;  and  c,  the  middle  part  of  the  white  or 
medullary  portion  of  the  brain ;  y,  f,  f,  f,  the  gray,  cineritious,  cortical  or  outer  part 
of  the  brain ;  :r,  a  deep  fissure  extending  from  the  front  surface  of  the  brain  to  the 
bridge ;  t/,  a  similar  fissure  at  the  back  part. 

brains,  or  indeed  of  the  two  halves  of  a  brain.  Neither  does 
the  size  of  the  convolutions  or  the  depth  of  the  anfractuosities 
follow  any  rule.  The  depth  or  quantity  of  the  white  sub- 
stance varies  as  much. 

300.  Fig.  47,  represents  a  section  of  the  cerebrum  on  a 
plane  with  the  grand  bridge  or  commissure  which  unites  the 
two  hemispheres.  It  is  called  the  corpus  callosum.  It  seems 
to  be  composed  mostly  of  white  fibres  like  the  nervous  fila- 
ments. Many  theories  have  been  advanced  in  regard  to  its 
use — probably  all  inventions. 

801.  If  a  section  be  made  a  little  deeper,  what  are  called 
5 


ORGANS  OF  VOLUNTARY  MOTION. 
Fig.  48. 


[CHAP.  t. 


Fig.  48.— S  represents  the  scalp,  next  to  which  is  seen  the  skull  or  cranium  (s,  s). 
M,  m,  A  part  of  the  membrane  lining  the  skull  and  covering  the  brain.  L  H,  Left 
hemisphere  of  the  brain.  R  H,  A  small  portion  of  the  right  hemisphere  seen  beyond. 
F,  The  deep  fissure  in  which  the  falx  is  situated. 

the  ventricles  will  be  brought  to  view  (Fig.  49.)  These  are 
frequently  spoken  of  as  cavities,  which  expression  is  apt  to 
convey  a  wrong  idea — as  the  sides  of  the  ventricles  are  al- 
ways in  contact,  except  they  are  separated  by  unhealthy 
collections,  which  sometimes  are  to  be  found  within  them. 
The  ventricles  are  lined  with  what  is  like,  and  called,  a  serous 
membrane — some  consider  it  a  continuation  of  the  pia  mater 
and  arachnoid;  some  consider  it  has  no  connection  with 
them.  The  ventricles  have  also  several  branches,  called 
horns,  leading  off  into  different  parts  of  the  brain. 

302.  Forming  the  bottom  of  each  ventricle,  are  found 
various  parts  of  divers  forms,  sizes,  and  colors,  helping  to 


SEC.  3.] 


THE  BRAIN  AND  NERVES. 
Fig.  49. 


99 


Fig.  49. — Section  of  the  skull,  A,  A ;  the  membranes,  B,  B ;  the  gray  substance. 
C,  C ;  the  medullary  portion,  D,  D ;  the  posterior  horn,  E,  and  anterior  part,  F,  of 
the  ventricles.  The  cnoroid  plexus  ia  seen  at  G.  In  the  bottom  and  between  the 
ventricles  several  parts  are  seen,  but  their  use  is  not  known. 

make  up  the  entire  cerebrum.  To  name  them  and  specu- 
late upon  their  use,  is  all  that  science  has  yet  done  in  respect 
to  them.  At  the  lower  part  of  the  brain,  are  also  seen  com- 
missures ;  their  utility  is  not  known. 

303.  At  the  bottom  of  the  skull,  the  brain  is  united  with 
the  spinal  cord  by  an  enlargement  of  it,  called  the  medulla  ob- 
longata,  or  oblongated  marrow.    They  are  here  also  connected 
with  each  other.     But  examinations  hereabouts  have,  as  yet, 
proved  very  unsatisfactory;   for  barren  description  is  very 
bootless.     We  can  only  infer,  that  there  is  free  opportunity 
for  communication  between  all  the  parts  connected  with  each 
other ;    but  how  much  influence  they  exert  upon  each  other, 
and  in  what  way,  is  unknown. 

304.  If  a  perpendicular  section  of  the  cerebellum  be 


100  ORGANS  OP  VOLUNTARY  MOTION.  [CHAP.  i. 

made,  a  trunk  of  white  substance  is  seen  in  the  middle  with 
branches  extending  on  either  side,  from  which  smaller 
branches  stretch  to  the  surface.  The  inter-space  is  occu- 
pied by  gray  substance — internally  producing  the  appear, 
ance  called  arbor  vitae,  or  tree  of  life  ; — and  externally,  the 
striped  appearance  of  which  I  have  spoken. 

305.  The  white  substance  throughout  the  brain  is  fibrous 
for  the  most  part.     A  great  number  of  fibres  radiate  from 
the  medulla  oblongata,  upward  and  outward  toward  the  con- 
volutions.     Some  suppose  that  these  arrive  at  the  gray  sub- 
stance, and  then  curve  around  and  pass  over  to  the  other 
half,  and  become  continuous  with  its  fibres,  thereby  forming 
the  corpus  callosum.     This  is  by  no  means  certain. 

306.  The  office  of  the  cerebrum  in  producing  motion,  is 
unknown.     The  effects  of  experiments  upon  animals  seem 
to  prove,  that  the  removal   of  large   portions  of  the  upper 
parts  of  the  large  brain,  has  no  effect  upon  the  production  of 
motion — frogs  leap  about,  as  if  nothing  had  happened,  and 
Magendie  asserts,  that  carp  swim  as  usual.     But  if  certain 
of  the  lower  parts  of  the  cerebrum  just  in  front  of  the  upper 
part  of  the  medulla   oblongata   be  cut,   the  animal  rushes 
forward  or  attempts  to  crawl  if  resisted,  remaining  in  the 
attitude  of  onward  motion. 

307.  The  office  of  the  cerebellum  seems  to  be  a  little 
mole  decided.     It  seems  to  exert   an  especial  influence  in 

.producing  the  involuntary  motions  of  the  voluntary  muscles. 
Hundreds  of  these  are  performed,  of  which  we  take  no 
notice.  While  addressing  an  audience,  a  person's  mind 
seems  to  be  abundantly  occupied  with  the  subject  of  his 
discourse  and  its  delivery,  and  the  balancing  of  the  body 
which  requires  the  constant  action  of  hundreds  of  muscles, 
seems  no  more  to  be  controlled  by  him,  than  in  case  of  him 
who  walks  while  asleep.  In  the  case  of  every  one  there  are 
many  movements  constantly  produced,  when  he  is  reclining 


SEC.  3.]  THE  BRAIN  AND  NERVES.     .  101 

in  the  easiest  position,  and  overcome  by  the  soundest  sleep. 
There  is,  also,  awake  or  asleep,  a  constant  action  of  the 
muscles,  to  a  greater  or  less  degree,  as  is  evident  from  the 
gaping  of  a  wound.  That  involuntary  and  unpractised 
influence  may  control  the  muscles,  is  certain — as  we  see 
evidence  of  it  in  animals  that  walk  as  soon  as  born. 

308.  Flourens  observed,   that  irregular  motions  were 
produced  as  soon  as  an  effect  was  apparent  in  the  cerebel- 
lum of  birds,  with  transparent  skulls,  which  he  had  forced 
to  take  alcoholic  drinks.     If  injuries  be  inflicted  on  the  small 
brain,  the  like  irregularities  will  result.     If  the  portion  of 
the  cerebellum  on  the  right  side,  riear  to  the  oblongata,  be 
cut,  the  animal  begins  to  revolve  towards  the  left.     If  the 
similar  part  on  the  left  side   be  cut,  the  animal  revolves 
towards  the  right.     Magendie  says,  he  has  seen  these  revo- 
lutions as  rapid  as  fifty  in  a  minute,  and  continue  eight  days. 
If  the  parts  on  both  sides  be  cut  at  the  same  time,  the  animal 
is  quiet,  but  unable  to  stand  or  walk. 

309.  If  injuries  be  inflicted  upon  certain  back  and  under 
portions  of  the  cerebellum,  the  movements  of  the  animal  will 
be  backward — birds  will  attempt  to  fly  backward.     There 
seem,  as  Magendie  thinks,  to  be  certain  parts  from  which 
influence   is   continually   exerted   upon  certain   classes  of 
muscles,  the  action  of  which  will  produce  certain  motions ; 
but  this  is  counteracted  by  the  opposing  action  of  another 
class.     The  effects  of  certain  diseases,  seem  to  prove  the 
correctness  of  this  opinion.     Horses  are  sometimes  so  affected 
by  disease  that  they  will  not,  and  apparently  cannot,  move 
backward.     Most  persons  must  have  seen  cats,  when  seized 
with  what  are  called  fits,  fly  with   the  utmost  impetuosity 
round  and  round,  or  off  in  a  tangent,  regardless  of  obstacles. 
I  have  seen  dogs,  also,  seized  with  the  same  impetuous  and 
apparently  involuntary  influences. 

310.  By  this  time,  the  reader  will  perceive  that  no  very 


102  ORGANS  OF  VOLUNTARY  MOTION.  [CHAP.  I. 

lucid  description  of  the  functions  of  the  brain  can  be  ex- 
pected. The  results  of  apoplexy,  and  other  diseases  and 
irregularities  of  the  brain,  convince  us  that  healthy,  vigorous 
action  of  the  muscles,  cannot  take  place  without  a  healthy 
condition  of  the  brain  exist.  The  debilitating  effects  of 
alcohol,  tea,  coffee,  tobacco,  &c.,  upon  the  nervous  system 
are,  among  other  ways,  exhibited  by  tremulousness  of  the 
hands  and  general  weakness  of  the  muscular  system.  Parts 
at  the  base  of  the  brain — how  numerous  or  how  extensive 
we  cannot  tell — exert,  without  doubt,  a  constant  influence 
upon  the  muscles ;  which,  increased  in  frs  power,  produces 
what  may  be  called  active  contraction  of  the  muscles. 
These  parts,  or  the  whole  brain,  act  likewise  upon  the  cord, 
influencing  its  condition ;  for  in  man  the  cord  seems  to  be 
powerless,  except  connected  with  the  brain :  but  influenced 
by  this  connection  with  the  brain,  the  cord  is  the  immediate 
source  or  centre  from  which  the  muscles  are  many  times 
influenced.  The  office  of  the  cord  and  brain,  or  of  certain 
parts  of  them,  seems  to  be  different,  or  differently  influenced, 
in  man  and  animals;  indeed,  in  different  species  of  ani- 
mals. 

311.  Whether  the  frequent  and  proper  action  of  the 
brain,  in  producing  muscular  contraction,  increase  its  size, 
has  not  been  shown.  Apparently,  no  effect  of  that  kind  is 
produced.  If  the  same  cause  produce  rapid  changes  of  the 
brain,  cannot  be  positively  asserted.  We  can  only  infer  that 
it  does,  from  the  fact,  that  in  case  of  muscular  action  there 
is  an  increased  flow  of  blood,  through  the  head.  As  this 
blood  returns  of  a  different  color  and  quality  from  what  it 
was,  a  logical  deduction  may  be  drawn  that  the  brain  has 
undergone  corresponding  changes.  On  the  other  hand,  an 
increased  circulation  of  blood,  as  when  alcoholics  have  been 
taken,  produces  increased  muscular  activity ;  so  also  in  brain 
fever,  or  other  diseases  attended  with  active  circulation  of 


SEC.  3.]          THE  BRAIN  AND  NERVES.  103 

blood  through  the  brain.  Apoplexy  and  opiates,  attended 
with  stagnation  of  blood  in  the  head,  not  only  produce  stupor 
of  the  senses,  but  complete  inaction  of  the  muscles  by  any 
voluntary  influence. 

312.  There  seems  to  be  no  doubt,  therefore,  but  a  pro- 
per circulation  of  good  blood,  through  the  brain,  is  neces- 
sary for  the  accomplishment  of  its  duties  in  producing  mus- 
cular action.  How  admirable,  that  increased  muscular  ac- 
tion increases  the  rapidity  with  which  the  blood  flows  to  the 
brain  at  the  very  time  required!  It  hence  follows,  that 
rubbing  the  body  and  general  exercise  of  the  system  must  be 
highly  favorable  to  the  brain.  Hereafter  it  will  be  seen,  that 
cultivation  of  the  mind  increases  the  circulation  of  blood  in 
the  brain,  and  thereby  increases  its  efficacy  in  fulfilling  its 
duties  in  connection  with  labor.  Nor  less  important  will  be 
a  cheerful  disposition,  for  a  merry  heart  sends  the  blood 
coursing  briskly  through  every  organ. 


CHAPTER  II. 

THE    ORGANS    OF    SENSATION    OR    FEELING. 
General  Observations. 

It  is  exceedingly  difficult  to  give  a  concise,  yet  plain  description,  of 
the  apparatus,  by  means  of  which  a  person  feels.  If,  however,  the  reader 
will  carefully  follow  me,  step  by  step,  I  will  endeavor  to  explain,  clearly 
as  possible,  all  that  is  known  of  the  manner  in  which  he  sees,  hears, 
smells,  tastes,  feels  pain,  or  has  any  kind  of  feeling  or  sensation. 

It  is  evident  to  every  one,  that  if  his  foot  be  hot,  his  mind  knows  it ; 
or  if  his  foot  be  cold,  his  mind  knows  that ;  or  if  the  temperature  of  hia 
foot  be  comfortable  and  right,  his  mind  knows  that.  If  his  hand  be  cold, 
or  hot,  or  comfortable,  his  mind  knows  it ;  but  his  mind  is  not  in  the 
foot  or  hand ;  for  if  either  be  removed,  he  has  the  same  mind  as  before. 
Other  like  arguments  would  prove  that  the  mind  has  its  seat  nowhere, 
except  in  or  at  the  brain.  How  then  can  the  mind  know  if  the  foot  be 
hot  or  cold  1  If  the  foot  be  pinched,  the  mind  knows  that ;  if  the  hand 
be  cut,  the  mind  knows  that,  and  if  there  be  any  thing,  right  or  wrong, 
in  any  part  of  the  body,  the  mind  knows  it  at  once.  There  must  be 
something,  therefore,  which  makes  the  mind  know,  at  its  seat  in  the  brain, 
if  the  foot  be  hot  or  cold,  bruised  or  sound ;  which  makes  the  mind  know 
the  state  of  every  part  of  the  body.  The  organs  or  apparatus  for  produc- 
ing sensations  or  feelings  do  this.  They  connect  all  parts  of  the  body  with 
the  mind.  Thus,  no  part  of  the  body  can  be  in  any  state,  without  pro- 
ducing an  effect,  through  the  organs  of  sensation,  on  the  mind  ;  hence, 

313.  The  organs  of  sensation  or  feeling  are  of  use,  in  the 
first  place,  to  cause  every  state  or  condition  of  the  body  to 
produce  on  the  mind  an  effect  called  a  sensation. 

314.  If  a  particle  of  dust  fall  into  the  eye,  it  produces  a  bad  state 
in  this  part  of  the  body,  and  this  will  produce  an  effect  on  the  mind, 
called  a  sensation.  If  the  stomach  be  overloaded  with  food,  an  effect 


GENERAL  OBSERVATIONS.  105 

called  a  sensation  is  produced  on  the  mind  ;  if  a  finger  be  cut,  a  sen- 
sation is  caused  ;  if  the  finger  be  pinched,  a  sensation  of  another  kind  is 
caused  ;  if  the  finger  be  cold,  still  another  sensation  is  produced.  If 
disease  attack  any  part,  it  produces  peculiar  sensations,  differing  accord- 
ing to  the  disease  and  the  part  affected.  Thus,  by  the  different  effects  or 
sensations  produced,  the  mind  learns  every  thing  it  knows  about  the 
condition  of  the  body,  and  of  course,  the  more  perfect  the  effects  or  sen- 
sations are,  the  better  does  the  mind  know  the  condition  of  the  body. 

But  again,  it  is  evident  to  the  reader  that  there  is  a  book  before  him, 
his  mind  knows  that  there  are  letters  upon  its  pages  ;  his  mind  also 
knows  the  color,  form,  and  odor  of  a  rose  ;  his  mind  knows  that  sugar  is 
sweet  and  vinegar  sour.  How  is  this  ?  His  mind  is  at  the  brain.  Does 
he  say  that  light  comes  from  the  book,  and  from  its  pages,  and  from  the 
rose,  into  his  eye,  and  thus  he  sees  ?  But  this  does  not  explain  the 
whole  operation.  The  light  only  comes  into  the  eye,  it  does  not  go  to 
the  brain.  Does  he  say,  that  he  smells  the  odor  of  the  rose,  because  it 
comes  up  into  his  nostrils  ?  But  the  odor  does  not  act  on  the  brain. 
How  then  does  the  odor  produce  an  effect  on  the  mind  ?  Does  he  say  that 
he  tastes  the  sugar,  because  it  is  put  in  his  mouth  1  But  the  sugar  dis- 
solves in  the  mouth  and  remains  there,  except  he  remove  it  by  swallow- 
ing or  otherwise.  How  does  he  know  that  the  ice  he  touches  is  cold  1 
How  does  he  know  his  foot  is  tickled  ?  There  must  be  means  of  con- 
necting all  parts  of  the  body  with  the  mind.  Thus,  when  light  acts  on 
the  eye,  there  must  be  something  which  produces  a  corresponding  effect 
on  the  mind.  There  must  be  something  which  makes  the  mind  know 
when  sugar  is  placed  in  the  mouth,  when  ice  touches  the  hand,  or  any 
part  of  the  body.  The  mind  knows  these  things  by  means  of  the  organs 
of  sensation.  By  the  same  means  it  knows  all  the  effects  which  objects 
around  us,  both  at  a  distance  and  near  at  hand,  produce  upon  the  body ; 
thus, 

315.  The  second  duty  of  the  organs  of  sensation  or 
feeling  is,  to  cause  surrounding  objects  to  produce  on  the 
mind  effects,  called  sensations. 

316.  The  roll  of  thunder  and  the  flash  of  lightning,  produce  effects 
on  the  organs  of  sensation  ;  and  they  then  produce  effects,  called  sensa- 
tions, on  the  mind — which  inform  it  of  the  approaching  storm.  Through 
the  organs  of  sensation,  or  feeling,  a  piece  of  ice  placed  on  the  hand  pro- 
duces an  effect,  called  a  sensation,  on  the  mind — which  informs  of  its 
coldness :  at  the  same  time  it  produces  another  kind  of  sensation,  which 

5* 


106  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

informs  of  its  weight,  and  still  another  kind,  which  informs  of  its  color, 
size,  form,  &c.  One  person's  voice  produces  one  sensation,  and  the 
mind  knows  its  friend  ;  another  person's  voice  produces  another  sensa- 
tion, and  the  mind  distinguishes  its  enemy.  A  rose  produces  a  sensa- 
tion of  smell,  that  informs  the  mind  of  its  odor;  another  sensation 
informs  of  its  color  ;  another  of  its  delicacy,  when  touched.  Camphor 
produces  different  sensations,  of  all  these  kinds,  and  thus  reveals  to 
the  mind  its  qualities.  Sugar  produces  sensations  ;  vinegar,  different 
ones.  Thus  by  sensations,  the  mind  learns  all  that  it  knows  of  the 
objects  surrounding  us — what  and  where  they  are.  Indeed,  knowledge 
of  an  object  means,  to  know  the  kinds  and  degrees  of  sensations  it  is 
capable  of  producing  in  the  mind,  through  the  organs  of  sensation,  and 
to  this,  is  our  knowledge  of  objects  limited.  The  man  born  deaf,  cannot 
know  the  important  qualities  or  properties  of  the  violin  ;  for  its  music  has 
never  produced  a  sensation  in  his  mind.  He  has  a  mind,  but  there  are 
no  means  of  connection  between  the  violin  and  his  mind,  such  that  it 
can  produce  sound.  Some  of  the  organs  of  sense  are  wanting,  or  in- 
capable of  producing  an  effect  on  the  mind.  The  portals  of  his  ears  are 
closed. 

317.  Objects  surrounding  us,  do  not  therefore  act  directly 
on  the  mind ;  and  consequently  do  not  produce  any  direct 
effect,  or  sensation  on  the  mind.  They  produce  an  effect  on 
some  part,  or  parts  of  the  body,  viz.,  on  some  of  the  organs 
of  sensation ;  these  produce  an  effect  on  the  mind.  The 
effect  which  objects  produce  on  the  organs  of  sensation,  is 
called  an  impression. 

We  so  constantly  say,  we  feel  this,  or  that  thing — a  piece  of  ice  for 
instance — that  we  often  think  we  feel  the  ice.  But  the  ice  touches 
the  skin,  not  the  mind  ;  yet  it  is  the  mind  that  feels.  What  then  does 
the  mind  feel,  if  it  do  not  feel  the  ice  ?  It  feels  the  effect  which  the  ice 
produces  or  causes  to  be  produced,  on  the  organs  of  sensation.  If  a 
string  that  I  pull,  be  fastened  to  a  boy's  finger,  he  says,  perhaps,  I  pull 
his  finger.  This  is  well  enough  in  common  conversation.  It  is  not, 
however,  strictly  correct :  I  pull  the  string,  to  be  sure ;  yet  it  is  not  I,  but 
the  string  that  pulls  his  finger.  I  make  the  string  pull  the  finger.  So 
the  ice  makes  the  body  produce  an  effect  on  the  mind  ;  yet  the  ice  does 
not  directly  act  on  the  mind.  I  may  cause  a  pin  to  prick  a  person,  and 
he  may  say  7  am  pricking  him  ;  but  it  is  not  correct.  It  is  the  pin  that 


GENERAL  OBSERVATIONS.  107 

pricks  him.     A  ball  may  hit  a  person.     He  cannot  properly  say,  the 
person  who  threw  the  ball,  hit  him. 

318.  The  effect  or  sensation  produced  by  the  organs  of 
sensation  on  the  mind,  when  the  object  acts  upon  them,  will 
depend,  therefore,  in  the  first  place,  upon  the  nature  or  pro- 
perties of  the  object ;  and  in  the  next  place,  upon  the  condi- 
tion and  nature  of  the  organs  of  sensation. 

319.  That  different  objects  would  produce  different  effects  on  the 
body,  is  too  evident  to  require  remark.  It  would  not  be  expected  that 
boiling  water  and  ice  would  produce  the  like  effects  on  the  body.  But 
it  is  not  so  easily  seen  that  the  effect  or  sensation  which  the  ice  or  boiling 
water  causes  the  body  to  produce  on  the  mind,  depends  on  the  nature 
and  condition  of  the  body,  or  of  some  of  those  parts  of  it,  called  organs 
of  sensation.  But  if  the  hand  be  numb  with  cold,  as  on  some  winter's 
day,  do  things  feel  the  same  as  when  the  hand  is  comfortably  warm  1 
If  a  person  be  sick,  does  not  the  weather  feel  more  chilly  to  him  than  it 
would  if  he  were  well  I  Any  person  may  try  the  experiment  of  putting 
one  hand  in  hot  and  the  other  in  cold  water  at  the  same  time,  and  then 
plunging  them  in  water  neither  cold  or  hot.  This  will  not  cause  the 
same  sensations  to  be  produced  through  one  hand  as  are  produced  through 
the  other.  But  the  water  that  acts  upon  one  is  precisely  the  same  as 
that  acting  on  the  other.  Why,  then,  the  difference  in  the  sensations  ? 
Because  the  condition  of  that  part  of  the  body  through  which  one  sen- 
sation is  produced,  is  different  from  the  condition  of  that  part  of  the 
body  through  which  the  other  sensation  is  produced.  If  a  person  have 
a  severe  cold,  a  rose  does  not  produce  its  ordinary  effect ;  not  be- 
cause the  rose  is  at  fault,  but  because  that  part  of  the  body  through 
which  the  sensation  of  smell  should  be  produced,  is  changed  from  healthy 
to  unhealthy.  If  objects  act  upon  the  body  when  it  is  not  in  a  healthy 
condition  on  any  account,  the  sensations  which  result  must,  therefore,  be 
unnatural. 

320.  But  the  nature  as  well  as  the  condition  of  the  parts 
through  which  sensations  are  caused,  determine  the  character 
of  the  sensation. 

If  a  rose  be  put  in  the  mouth,  its  odor  does  not  produce  any  effect, 
because  it  is  not  the  nature  of  the  organs  of  sensation  upon  which  the 
rose  acts  in  the  mouth,  to  cause  any  sensation  of  smell.  If  a  bow  be 
drawn  on  the  back  of  a  violin,  it  does  not  cause  any  music.  To  produce 


108  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

that,  the  bow  must  be  drawn  upon  the  strings,  for  they  were  made  for  the 
purpose.  The  odor  of  the  rose  must  for  the  same  reason  be  applied  to 
the  nose,  for  the  organs  of  sensation  which  connect  between  the  nose 
and  mind  have  been  made  so  as  to  act  on  the  mind  when  the  odor  of  a 
rose  acts  on  them.  If  the  eyes  be  shut  and  the  mouth  open,  light  can 
pass  into  the  mouth,  but  yet  a  person  cannot  see,  because  the  organs 
that  connect  between  the  month  and  mind,  if  acted  on  by  light,  have 
not  been  made  so  as  to  act  on  the  mind  when  light  acts  on  them.  But 
the  organs  connecting  betweeu  the  eye  and  mind  are  acted  on  by  light, 
and  are  so  constituted  that  when  acted  on  by  light,  they  will  act  on  the 
mind.  Certain  parts  of  the  body  will  produce  the  sensation  of  tickling 
when  acted  on  in  a  certain  manner,  which  other  parts  will  not.  Thus 
the  effect  or  sensation  produced  on  the  mind,  by  the  action  of  any  object 
upon  the  body,  will  essentially  depend  upon  the  nature  or  constitution  of 
the  organs  of  sensation  acted  on.  From  this  paragraph  it  is  also  to  be 
inferred  that  there  are  several  classes  of  organs  of  sensation,  differing 
from  each  other  in  their  nature. 

321.  Observe  also,  that  any  state  of  the  body  does  not 
act  on  the  mind  directly,  but  on  the  organs  of  sensation, 
which  act  on  the  mind. 

An  overloaded  stomach  does  not  act  on  the  mind  directly.  To  be 
sure  we  say  this  or  that  part,  for  instance  a  tooth,  aches  ;  but  this  is 
not  so.  The  tooth  acts  on  the  organs  of  sensation,  and  they  cause  the 
ache.*  If  a  particle  of  dust  be  in  the  eye,  we  say  the  eye  smarts ; 
strictly  speaking  it  is  not  so ;  the  eye  acts  on  certain  organs  of  sensa- 
tion connecting  between  it  and  the  mind;  these  produce  an'effect  on  the 
mind.  Thus,  any  healthy  or  diseased  part  of  the  body  produces  effects 
on  the  organs  of  sense,  connecting  between  the  part  and  the  mind,  and 
these  organs  produce  an  effect,  sensation,  or  feeling  on  the  mind. 

322.  The  effect  or  sensation  which  any  part  of  the  body 
will  cause  to  be  produced  on  the  mind,  will  depend  on  the 
condition  of  the  part  acting  on  the  organs  of  sensation,  and 
upon  the  nature  and  condition  of  these  organs. 

*  Perhaps  the  reader  will  object,  that  he  really  has  felt  the  tooth 
ache  ;  that  the  ache  was  in  the  tooth  and  nowhere  else.  The  reason  of 
this  was,  that  we  are  so  made  as  to  feel  the  ache  in  the  part  where, 
as  a  usual  thing,  the  cause  originating  the  ache  first  acts.  Sometimes  it 
is  not  so ;  but  this  matter  will  be  treated  upon  in  its  proper  place. 


GENERAL  OBSERVATIONS.  109 

323.  That  a  healthy  condition  of  any  part  of  the  body  would  pro- 
duce a  different  effect  on  the  organs  of  sensation,  from  that  produced  by 
an  unhealthy  state  of  the  same  part,  or  that  two  kinds  of  diseases  of  any 
part,  acting  at  different  times  upon  the  organs  of  sensation,  would  pro- 
duce different  effects  or  impressions  upon  them,  is  too  evident  and  too 
often  experienced  to  require  proof  or  remark.     But  it  is  important  that 
it  be  as  clearly  seen,  that  the  effect  produced  upon  the  mind  depends  also 
upon  the  nature  and  condition  of  the  organs  of  sensation.    Thus,  in  case 
of  disease,  when  a  person  has  chills,  as  they  are  called,  he  stands  before 
the  fire,  but  gains  no  comfort,  though  his  body  be  heated.     The  dis- 
eased condition  of  the  organs  of  sensation  prevents  them  from  produc- 
ing the  sensation  of  warmth  in  the  mind,  though  they  are  acted  on  by 
heat.     A  person  afflicted  with  neuralgia  has  a  tooth  drawn,  in  hopes  of 
stopping  the  pain,  but  finds  his  hopes  vain.  '  It  is  the  diseased  condition 
of  the  organs  of  sensation  which  produces  the  painful  sensation  upon 
the  mind.     This  is  proved  by  the  fact,  that  as  soon  as  the  condition  of 
the  organs  of  sensation  is  changed  for  the  better,  the  painful  are  ex- 
changed for  agreeable  sensations. 

324.  But  the  nature  of  the  organs  of  sensation  is  still  more  worthy 
of  notice.      If  the  skin  be  pricked,  pinched,  bruised,  burned,  or  the 
like,  when  in  a  natural  or  healthy  condition,  the  organs  of  sensation, 
connecting  between  the  skin  and  mind,  will  be  acted  on,  and  will  also 
act  on  the  mind,  producing  sensations.     If,  however,  the  tendon  on  the 
back  of  the  hand,  or  any  other  tendon  be  exposed,  it  will  be  fouud  by 
experiment,  that  it  may  be  pricked,  pinched,  bruised,  and  even  acted  on 
by  burning  heat,  and  the  person  not  know  it.     The  organs  of  sensation, 
connecting  between  the  tendons  and  the  mind,  may  be  acted  on,  for 
aught  we  know,  but  their  nature  is  such  that  they  produce  no  effect  upon 
the  mind.     But  if  the  tendon  be  twisted  a  very  little,  the  mind  will 
know  it,  for  the  organs  of  sensation  connecting  between  the  tendons  and 
th",  mind  have  been  made  so  as  to  be  acted  upon,  and  to  act  on  the 
mind,  under  such  circumstances.     If  a  healthy  bone  be  cut,  the  mind 
does  not  know  it ;  because  the  organs  of  sensation  connecting  the  bone 
with  the  mind  have  been  so  made,  that  if  acted  on,  when  the  healthy 
bone  is  cut,  they  produce  no  effects  on  the  mind.     If,  however,  the  bones 
be  diseased  or  broken,  the  organs  of  sensation  produce  effects  on  the  mind 
if  the  bones  are  moved  in  the  slightest  degree  ;  for  this  is  their  nature  or 
constitution — they  have  been  so  made.     Persons  have  sometimes  died 
of  diseases  of  the  heart,  which  they  have  had  for  years,  and  yet  no  one 
knew  it  till  it  was  learned  by  post  mortem  (after  death)'  examination. 


IK)  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

The  organs  of  sensation,  connecting  between  the  heart  and  mind,  were 
not  so  made  as  to  act  on  the  mind  in  such  cases.  Reasons  why  these 
things  should  be  so  will  be  hereafter  given.  Thus  the  effect  upon  the 
mind,  which  any  part  of  the  body  will  cause  to  be  produced,  will  depend 
in  the  first  place  on  the  condition  or  state  of  the  part ;  in  the  second 
place,  upon  the  condition  of  the  organs  of  sensation,  and  in  the  third 
place,  upon  the  nature  of  those  organs.  From  the  facts  adduced  in  this 
paragraph  it  is  also  to  be  inferred,  that  there  are  several  classes  of  organs 
of  sensation,  each  gifted  with  different  powers,  by  which  each  one  be- 
comes efficient  in  its  own  way. 

325.  The  next  question  to  answer,  is,  How  do  objects  act 
on  the  organs  of  sensation,  and  how  do  they  act  on  the  mind  ? 
This  is  not  known.  But  to  form  as  reasonable  a  conjecture 
as  possible,  we  must  first  notice,  what  is  necessary  to  produce 
a  sensation  in  the  natural  course,  viz.,  mind,  brain,  a  nerve, 
an  organ  of  sense,  and  an  object. 

326.  It  is  thus  seen  that  several  parts  are  necessary  to  form  the 
organs  of  sensation,  viz.  the  brain  or  nerve,  and  organ  of  sense  ;  and  in 
the  order  in  which  they  stand  in  the  preceding  paragraph,  they  are  be- 
tween the  object  and  mind.     The  mind  is  to  be  acted  on,  the  object  is 
to  cause  the  mind  to  be  acted  on.     It  does  cause  the  mind  to  be  acted 
on,  by  acting  on  the  organ  of  sense*  which  acts  on  the  nerve,  which 
acts  on  the  brain,  which  acts  on  the  mind.     Thus  it  will  be  seen,  that 
if  the  organ  of  sense  be  wanting  as  in  Fig.  50,  the  object  cannot  pro- 
duce an  effect  on  the  nerve,  or  if  the  nerve  be  wanting,  an  effect  can- 
not be  produced  by  the  organ  of  sense  on  the  brain,  or  if  the  bi*ain  be 
wanting,  an  effect  cannot  be  produced  on  the  mind,  and  of  course,  if 
the  mind  be  wanting,  no  effect  can  be  produced  upon  it.     These  things 
are  proved  in  various  ways.     In  the  first  place,  to  produce  a  sensation, 

327.  The  mind  is  necessary ;  for  if  the  mind  be  entirely  occupied 
with  any  business,  a  friend  may  speak  and  his  voice  is  not  heard.     Of 
course,  it  produces  an  effect  on  the  organ  of  sense,  and  that  produces  an 
effect  on  the  nerve,  which  produces  an  effect  on  the  brain,  but  that 
causes  no  effect,  which  acts  on  the  mind  and  is  perceived. 

328.  The  brain  is  necessary,  as  is  evident  when  any  derangement  of 
it  is  produced  by  accident,  disease  or  medicine.   An  insane  person  walks 

*  This  has  nearly  the  same  name  as  organs  of  sensation,  but  is  only 
one  of  the  organs  of  any  sensation. 


GENERAL  OBSERVATIONS.  Ill 


barefooted  on  the  frozen  ground,  and  though  frostbitten,  teels  no 
tion.  Opium,  and  its  like,  act  on  the  brain,  so  as  to  prevent  it  from 
acting  on  the  mind.  The  physician  takes  advantage  of  this  quality 
of  various  medicines,  to  lull  pain,  as  the  expression  is.  Perhaps,  and 
probably,  an  effect  is  produced  on  the  nerves  at  the  same  time  which 
prevents  them  from  acting  on  the  brain,  as  when  pain  is  produced. 

329.  A  nerve  is  necessary,  as  is  proved  by  cutting  the  nerve,  experi- 
mentally, in  case  of  animals,  and  accidentally  in  case  of  man,  and   by 
compressing  the  nerve.     A  sensation  is  not  then  produced  by  any  thing 
applied  to  the  part,  where  the  cut  nerve  commences  ;  e.  g.,  the  lady 
with  the  elbow  cut,  &c.,  mentioned  in  a  former  paragraph. 

330.  An  organ  of  sense,  is  the  name  given  to  the  part  in  which  the 
nerve  commences,  and  is  of  course  necessary.     It  is  sometimes  necessary, 
as  hereafter  seen,  to  direct  in  a  proper  manner,  the  action  of  an  object 
upon  the  nerve. 

331  The  necessity  of  an  object,  to  produce  an  effeet  on  the  organ 
of  sense,  or  through  the  organ  of  sense  upon  the  nerve,  is  too  obvious  to 
require  illustration. 

332.  It  is  important  now,  to  observe,  that  if  any  of  the  organs  of  a 
sensation  be  diseased,  the  kind  of  sensation  which  an  object  will  cause 
to  be  produced,  will  be  affected  thereby.     If  an  organ  of  sense  be  dis- 
eased, an  object  will  not  produce  the  same  effect  on  it   as  if  it  were 
healthy.     If  the  organ  of  sense  be  healthy,  but  the  nerve,  or  any  part 
of  it,  unhealthy,  the  effect  produced   on  the    brain  will   be  different 
from  what  it  would  be  if  the  nerve  were  healthy;  and  if  the  effect 
on  the  brain  be  different,  the  effect  the  brain   will  produce  on  the  mind 
will  be    different.     So,  also,  will  the  sensation   be   unnatural,  if  the 
brain  be  diseased.     That  is  to  say,  if  the  condition  of  the  organ  of 
sense,  the  nerve,  or  the  brain,  be  changed,  a  corresponding  effect  will 
be  produced   on  the   sensation.     When  sick,  therefore,  things  do  not 
taste,  smell,  or  feel  as  before ;   a  very  little   light  pains,  or  a  very 
low  sound  distresses.    It  is  very  important,  as  hereafter  seen,  that  the 
truths  of  this  paragraph  be  fully  appreciated  and  understood. 

333.  A  sensation  is  usually  produced  in  the  manner  shown  in  the 
preceding  paragraphs,  but  it  is  evident  that  if  the  brain  act  on  the  mind, 
a  sensation  will  be  produced,  even  if  a  nerve  have  not  acted  on  the 
brain.     So  likewise,  a  nerve  can  act  on  the  brain,  and  the  brain  will  then 
produce  an  effect  on  the  mind  if  the  organ  of  sense  have  not  acted  on  the 
nerve  ;  and  with  like  results  the  organ  of  sense  can  act  on  the  nerve,  if  an 
object  have  not  acted  on  it.     In  all  these  cases,  when  the  mind  perceive* 


112  ORGANS  OF  SENSATION  OB  FEELING.  [CHAP.  II. 

a  sensation,  it  will  believe  some  object  has  acted  on  the  organ  of  sense, 
because  it  is  usually  the  case,  and  because  it  has  been  so  made  as  to  think 
it  is  so.  Thus,  by  some  disease  of  some  part  of  the  organs  of  sensation,  a 
sensation  is  produced,  and  a  person  thinks  a  tooth  is  the  cause, because  the 
pain  is  like  toothache,  but  when  the  tooth  has  been  pulled,  he  learns  that 
his  idea  was  wrong.  From  a  disease  of  some  of  the  organs  of  sensation, 
a  person  will  feel  as  if  some  animals,  e.  g.  ants,  were  creeping  on  the  skin, 
but  it  is  not  so,  as  he  finds  by  examination  ;  thus 

334.  The  existence  and  character  of  sensations  will  de- 
pend, on  the  properties  of  acting  objects,  on  the  nature  and 
condition  of  the  organs  of-  sense,  nerves,  brain,  and  on  the 
mind. 

The  divisions  of  this  chapter  are  therefore  obvious. 


SECTION  1. — Sensations. 

335.  Any  effect  produced  on  the  mind,  by  or  through 
any  part  of  the  body,  is  called  a  sensation. 

Sensations  are  of  many  different  kinds :  of  hunger,  of  thirst,  of  pain, 
of  touch,  of  heat,  of  cold,  of  tickling,  of  nausea,  of  suffocation,  of  fulness, 
of  sweetness,  of  sourness,  of  a  rose,  of  camphor,  of  weight,  of  the  various 
colors,  of  sounds,  &c.,  &c. 

Sensations  of  the  same  kind  vary  greatly  in  intensity.  When  of 
such  a  degree,  as  to  be  quite  noticeable,  they  are  called  feelings.  If  the 
weather  be  perfectly  agreeable,  it  is  usual  to  say  it  produces  an  agree- 
able sensation,  but  if  it  be  cold  or  hot,  the  usual  expression  is,  it  feels 
cold  or  hot.  That  is  to  say,  a  strong  sensation  is  called  a  feeling. 

336.  Sensations   may  be  divided  into  two  grand  classes, 
pleasurable  or  delightful,  and  unpleasant  or  painful. 

337.  Pleasurable  sensations,  when  of  a  high  degree,  are 
called  delightful  feelings.     They  are  for  the  purpose  of  re- 
warding the  mind,  for  the  care  it  has  taken  of  the  body,  and 
inducing  a  continuance  of  the  same  care. 

338.  Pleasurable  sensations  are  produced  by  the  healthy 
condition  and  by  the  proper  action  of  any  part  of  the  body. 


SEC.  1.]  SENSATIONS.  113 

A  healthful  condition  of  any  part  of  the  body,  causes  the  organs  of 
sensation  to  produce  in  the  mind  that  peculiar  and  desirable  sensation, 
difficult  to  describe,  but  which  every  one  has  experienced,  when  he  says 
I  feel  well.  The  healthy  exercise  of  any  part  increases  the  same  sensa- 
tion. The  healthy  exercise  of  the  muscles  is  productive  of  great  plea- 
sure. He,  therefore,  who  pursues  a  sedentary  life,  fails  to  enjoy  all  that 
class  of  delightful  sensations  which  make  happier  the  life  of  him  who,  by 
daily  exercise,  improves  his  muscular  system.  He  not  only,  day  by  day, 
enjoys  the  sensations  attendant  upon  the  action  of  his  muscles  but  fits 
them  to  increase  the  pleasures  they  are  bestowing.  For  a  full,  healthy, 
daily  exercised  muscle,  causes  much  more  pleasurable  sensations,  and  for 
a  longer  time,  than  the  inefficient,  feeble  muscle.  There  is,  therefore, 
pleasure  in  labor ;  not  in  the  fatigue  of  laboring  too  long,  but  in  labor, 
such  as  a  man  ought  to  do.  The  often  exercised  ear,  adds  a  double 
charm  to  existence.  The  sensations  it  wakes  up,  thrill  the  soul,  almost 
to  ecstasy.  The  sensations  caused  by  light,  acting  on  the  eye,  are  highly 
pleasurable.  The  mind,  imprisoned  from  the  action  of  light,  and  shut 
out  from  all  the  delightful  sensations  it  causes,  soon  feels  a  gloom  all 
other  sensations  cannot  entirely  remove.  The  balmy  air  of  spring  time 
or  summer,  wafted  around  us,  and  bearing  to  our  nostrils  the  sweet 
fragrance  of  the  scented  fields,  acts  so  genially  upon  the  body,  that  the 
mind  is  satisfied  with  the  delicious  sensations  it  produces.  The  organs 
of  digestion,  while  acting  to  prepare  the  food  in  the  mouth,  or  after  it  is 
swallowed  to  the  stomach,  add  much  to  the  gratifications  of  life.  Nor 
is  there  a  small  degree  of  pleasure  felt,  when,  after  proper  action,  the 
exercised  organs  are  allowed  proper  repose.* 

*  I  cannot  help  transcribing  from  a  book,  so  common,  on  account 
of  its  value,  that  perhaps  a  reference  will  be  thought  sufficient ;  but 
Parker's  Exercises  may  not  be  known  to  every  one,  and  the  passage 
will  bear  more  than  one  reading : 

"  The  words  commonly  used  to  signify  diversion  are  these  three, 
namely,  relaxation,  amusement,  and  recreation ;  and  the  precise  mean- 
ing of  these  words  may  lead  us  to  very  useful  instruction.  The  idea  of 
relaxation  is  taken  from  a  bow,  which  must  be  unbent  when  it  is  not 
wanted  to  be  used,  that  its  elasticity  may  be  preserved.  Amusement 
literally  means  an  occasional  forsaking  of  the  Muses,  or  the  laying  aside 
our  books  when  we  are  weary  with  study ;  and  recreation  is  the  refresh- 
ing or  recreating  of  our  spirits  when  they  are  exhausted  with  labor,  that 
they  may  be  ready  in  due  time,  to  resume  it  again. 

"  From  these  considerations  it  follows  that  the  idle  man  who  has  no 
work  can  have  no  play ;  for,  how  can  he  be  relaxed  who  is  never  bent  ? 
How  can  he  leave  the  Muses  who  is  never  with  them  ?  How  can  play 
refresh  him  who  is  never  exhausted  with  business  ? 


114  ORGANS  OF  SENSATION  OR  FEELING  [CHAP.  II. 

339.  Pleasurable  sensations  dissipate  melancholy,  remove 
oppressive  feelings,  excite  the  action  of  the  system,  assist  di- 
gestion, tend  to  improve  health,  and  lengthen  life. 

The  physician  recommends  to  the  low-spirited  to  travel,  where  new 
and  pleasurable  sensations  and  a  variety  of  them  will  be  produced. 
"  The  smell  of  the  fresh  air,"  says  the  invalid,  "  makes  me  feel  better." 
The  odor  of  the  preparing  food,  if  agreeable,  excites  the  appetite ;  the 
taste  of  relished  food  causes  a  free  flow  of  saliva  into  the  mouth,  and  a 
free  flow  into  the  stomach  of  fluids  necessary  there,  for  a  further  prepa- 
ration of  the  food.  It  is  important,  therefore,  that  we  cultivate  an  appe- 
tite for  wholesome  food,  and  by  exercise  produce  a  relish  for  it ;  for  the 
agreeable  sensations  then  caused,  will  cause  the  food  to  be  more  readily 
and  perfectly  digested.  Indeed,  it  is  important  that  we  cultivate  all  our 
organs,  so  as  to  realize  the  greatest  possible  variety  and  the  highest  pos- 
sible degree  of  pleasurable  sensations. 

340.  It  must  not  hence  be  inferred  that  all  causes  of 
pleasurable  sensations  are  productive  of  health.     Some  things 
cause  pleasurable  sensations  at  first,  but  afterwards  very  un- 
pleasant sensations. 

Man  has  been  gifted  with  reason  and  intelligence,  the  cultivation  of 
which  is  attended  with  a  far  higher  degree  of  pleasure  than  is  produced 
by  exercise  of  the  body.  If  he  cultivate  these  by  acquiring  knowledge, 

"  When  diversion  becomes  the  business  of  life,  its  nature  is  changed  ; 
all  rest  presupposes  labor.  He  that  has  no  variety  can  have  no  enjoy- 
ment ;  he  is  surfeited  with  pleasure,  and  in  the  better  hours  of  reflection 
would  find  a  refuge  in  labor  itself.  And,  indeed,  it  may  be  observed, 
that  there  is  not  a  more  miserable,  as  well  as  a  more  worthless  being, 
than  a  young  person  of  fortune,  who  has  nothing  to  do  but  find  out 
some  new  way  of  doing  nothing. 

"  A  sentence  is  passed  upon  all  poor  men,  that  if  they  will  not  work, 
they  shall  not  eat ;  and  a  similar  sentence  seems  passed  upon  the  rich, 
who,  if  they  are  not  in  some  respect  useful  to  the  public,  are  almost  sure 
to  become  burthensome  to  themselves.  This  blessing  goes  along  with 
every  useful  employment ;  it  keeps  a  man  on  good  terms  with  himself, 
and  consequently  in  good  spirits,  and  in  a  capacity  of  pleasing  and  be- 
ing pleased  with  every  innocent  gratification. 

"  As  labor  is  necessary  to  procure  an  appetite  to  the  body,  there  must 
also  be  some  previous  exercise  of  the  mind  to  prepare  it  for  enjoyment ; 
indulgence  on  any  other  terms  is  false  in  itself,  and  ruinous  in  its  con- 
sequences. Mirth  degenerates  into  senseless  riot,  and  gratification  soon 
terminates  in  satiety  and  disgust." 


SEC.  1.]  SENSATIONS.  115 

he  will  learn  what  things  he  may  use,  and  how  he  may  use  them,  so  as 
to  promote  his  immediate  and  ultimate  happipess.  The  child,  finding  the 
seeds  of  the  thorn-apple,  and  being  ignorant  of  their  quality,  eats  many 
of  them  and  dies.  A  person  ignorant  of  the  nature  of  henbane,  culti- 
vated the  plant  by  his  door,  because  he  thought  "  the  berries  so  pretty." 
They  were  equally  attractive  to  his  child,  which  not  only  looked  at  them 
and  picked  them,  but  ate  them  ; — it  was  made  very  sick.  A  child  cries 
for  sweetmeats,  which  the  mother,  not  regarding  sufficiently  the  ultimate 
good  of  the  child,  allows  it  to  have  ;  sickness,  fits,  convulsions,  &c.,  fol- 
low  ;  while  those  of  more  knowledge,  know  it  their  duty,  but  still  more 
feel  it  their  pleasure,  to  watch  the  child  till  old  enough  to  heed  instruc- 
tion, when  they  carefully  teach  it  to  avoid  trouble -causing  things.  The 
young  man  who  sips  the  enticing  wine,  wishing  to  enjoy  the  hilarity  it 
will  produce  for  the  moment,  will  learn,  when  the  poor-house  is  his  pros- 
pective home — when  his  constitution  is  broken  down,  health  and  friends 
gone,  and  he  a  disgrace  to  himself  and  mankind — that  many  times 
"  present  pleasure  is  future  pain."  The  oyster  or  other  supper  may 
make  the  passing  hour  more  convivial ;  but  a  disturbed  sleep  and  break- 
fast without  appetite,  and  ere  long  a  dyspeptic  stomach,  will  teach  a  per- 
son that  man  cannot  long  be  affected  with  pleasurable  sensations,  with- 
out he  gain  knowledge,  and  practise  accordingly. 

341.  Pleasurable  sensations  tend  to  improve  the  disposi- 
tion. 

The  child's  mind  should  therefore  receive  a  great  variety  of  sensa- 
tions— all  those  kinds  which  will  not  prove  harmful  in  the  end.  It  should 
be  taught  to  love  the  flowers,  for  then*  beauty  and  then*  odor,  and  to  be 
charmed  with  the  scenery  of  nature.  When  very  young,  its  mind  should 
be  occupied  and  its  attention  taken  up  with  all  the  sensations  produced 
by  exercise,  by  new  sights  and  sounds,  by  playthings,  by  songs  and  mu- 
sic— whatever  will  interest  it,  without  producing  any  harm.  Its  mind  is 
almost  a  blank,  has  scarcely  a  thought,  is  almost  wholly  dependent  on 
sensations  produced  through  its  organs  of  sensation,  and  they  have  not 
yet  become  full  and  perfect.  If  it  have  no  other  sensations,  it  will  desire 
those  which  are  produced  by  eating  or  tasting ;  for  from  the  first  moment 
the  infant  mind  wakes  to  intelligence,  it  will  not  be  satisfied,  without  its 
attention  be  occupied  with  something.  If  the  child  desire  to  have  some 
sensation  produced  which  is  harmful,  its  attention  is  to  be  occupied  with 
some  other  sensation  which  will  make  it  forget  its  desire.  If  the  child's 
desire  be  denied,  without  its  attention  being  occupied,  it  will  fret,  and  its 


116  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

disposition  will  be  injured  ;  but  if  its  attention  be  called  off  by  some  new 
sensation,  which  is  not  harmful,  no  fretting  is  produced,  e.  g.t  if  a  child 
desire  sweetmeats,  and  they  are  put  out  of  its  reach  and  left  where  it 
can  see  them,  and  nothing  more  done,  it  will  have  a  cry  ;  while  if  some 
plaything  be  presented  before  it,  or  it  be  asked  to  go  and  walk,  or  in  any 
other  way,  if  its  attention  be  occupied  and  sensations  produced,  while 
the  sweetmeats  are  put  out  of  its  sight,  the  child  will  remain  pleasant. 
It  is  hence  seen  how  judicious  it  is  to  cultivate  our  physical  systems  in 
such  a  manner,  that  all  proper  sensations  shall  be  produced  in  an  intense 
degree  ;  for  though  the  pleasure  of  taste  and  smell,  of  touch  and  muscu- 
lar exercise,  of  sight  and  hearing,  may  not  rate  with  the  results  of  men- 
tal cultivation,  they  fit  the  body  to  better  serve  the  uses  of  the  mind  ; 
they  soften  the  disposition,  and  make  us  love  better,  ourselves,  our  fellow- 
men,  and  the  world  around  us,  which  is  so  pleasure-giving  to  the  healthy 
mind  in  a  healthy  body. 

342.  Pleasurable  sensations  produced  by  objects,  render 
them  attractive  to  the  mind. 

Hence  persons  may  not  only  produce  a  very  favorable  first  impres- 
sion, but  continue  to  render  themselves  agreeable,  by  dress  and  graceful 
manners,  and  by  ministering  to  the  sense  of  hearing,  taste,  and  smell. 
The  ear  is  beguiled  by  the  silver  tones  of  the  voice.  The  good  house- 
wife retains  the  love  and  affection  of  her  husband,  by  always  meeting  his 
appetite  with  delicious  food.  Many  a  heart  has  been  ensnared  by  the 
fragrance  exhaled  from  a  bouquet  of  beautiful  flowers,  arranged  by  still 
more  beautiful  hands.  Let  not  these  little  things  be  spurned.  We  may 
love  a  person  for  his  good-nature,  and  admire  his  intellect,  who  is  clown- 
ish. The  careless  woman  may  be  the  idol  of  her  husband,  for  she  may 
have  excellent  traits.  But  sensations  must  be  produced  on  every  mind, 
and  they  must  please  or  displease.  True,  habit  effects  much ;  but  God 
has  intended  that  every  class  of  the  organs  of  sensation  should  be  pro- 
ductive of  sensations,  and  he  will  not  allow  his  laws,  even  of  the  most 
minor  character  in  our  eyes,  to  be  trampled  upon  with  impunity.  If  one 
sensation  only,  displeases,  it  is  so  much  for  the  other  sensations  to  over- 
come. It  will  not  be  fruitless,  therefore,  to  study  the  means  by  which 
sensations  are  produced  and  perfected,  as  we  may  thereby  be  able  to 
make  ourselves  happier,  and  capable  of  rendering  others  happier. 

343.  Unpleasant  sensations.      When  these  are  intense, 
they  are  called  painful.     They  are  for  the  purpose  of  warn. 


SEC.  1.]  SENSATIONS.  117 

ing  the  mind  when  the  body  is  exposed  to  danger,  or  is  actu- 
ally injured.  The  causes  which  produce  them  may  be  con- 
sidered under  three  heads. 

344.  First.    Unpleasant  sensations  are  produced  when 
any  part  of  the  body  is  not  used  or  exercised  as  much  as  it 
should  be. 

If  the  muscle  be  not  exercised,  an  uneasiness,  a  discontentedness,  a 
dissatisfaction  with  one's  self,  with  the  world,  and  with  everybody  in  it,  is 
produced ;  sensations  difficult  to  describe,  and  still  more  difficult  to  bear 
with  a  pleasant  spirit.  It  may  be  called  an  appetite  for  the  exercise  of 
the  muscles.  The  lover  of  music  has  often  felt  the  unpleasant  sensations 
produced  by  want  of  exercise  of  those  organs  which  cause  sensations  of 
musical  sounds.  He  has  often  exclaimed,  "  I  feel  hungry  for  music." 
This  feeling  is  not  altogether  of  a  physical  nature,  if  I  may  use  such  an 
expression.  These  unpleasant  sensations  are  felt,  because  it  is  harmful 
to  a  person  to  have  the  organs  causing  such  sensations,  remain  longer 
without  exercise. 

345.  Second.  Painful  sensations  are  felt  when  any  part 
of  the  body  is  over-exercised  or  over-tasked. 

If  the  muscles  be  over-exercised,  they  first  produce  weariness,  then 
fatigue,  then  exhaustion.  The  slightly  unpleasant  sensation  of  weariness 
is  to  warn  when  the  muscles  have  acted  as  long  as  is  for  their  good, 
and  require  rest.  This  sensation  ought  never  to  be  increased  to  fatigue, 
much  less  to  exhaustion  ;  for  then  the  muscles  suffer,  and  sometimes  be- 
yond restoration.  Persons  have  been  so  much  excited  by  a  fire,  which 
was  destroying  their  property,  as  to  work  on  without  heeding,  or  indeed 
feeling  the  sensations  which  would  have  warned  of  danger,  till  exhausted 
by  labor,  they  have  sunk  down,  never  more  to  recover  perfect  strength. 
Whoever,  therefore,  takes  alcoholic  drinks  or  other  poisons,  that  they  may 
act  on  the  brain  and  prevent  the  sensation  of  weariness  from  being  pro- 
duced, does  himself  harm.  He  ought  to  feel  that  he  has  done  enough. 
The  poison  does  not  improve  the  muscle,  and  if  he  go  on  to  labor,  he  will 
lay  the  foundation  for  rheumatism,  and  many  other  complaints.  The 
housekeeper,  who,  tired,  thinks  to  relieve  herself  by  a  cup  of  tea,  and 
then  go  on,  and  finish  her  work,  exhausts  the  system,  and  if  she  do  not 
feel  the  exhaustion,  produces  at  last  a  sick  headache  or  like  evil,  lasting 
for  days,  perhaps.  Too  long-continued  action  of  any  organ,  exhausts  its 
power :  an  approach  to  this  is  notified  by  unpleasant  sensations. 


118  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

346.  Third.  Painful  sensations  are  produced,  when  any 

part  of  the  body  is  affected  by  accident,  or  is  suffering  from 

• 


T.n         ;V  "'••,"<•*•*     J'c  v     «4rtCr^'i«:/-"iU          ,  ..-"III      .fenii'>i     . 

When  the  body  is  in  the  immediate  vicinity  of  danger,  a  strong  sen- 
sation of  alarm  seizes  the'  mind,  and  impels  it  "to  caW  fof  the  body. 
Some  might  say  that  this  was  wholly  the  operation  of  the  mind.  But 
if  a  very  young  child  be  raised,  and  then  brought  down  c^ickly,  as  if  it 
were  falling,^  it  will  ..be  seen,  by  its  outstretched  arms,-to  be  jin  alarm.  It 
has  never  yet  fallen,  and  knows  aot  that  harm  will  follow,  bftt  a  sensation 
is  produced  by  certain  organs  of  sensation* -which  .have  been  made  to 
act  under  such  circumstances.  It  has  also  been,  shown  that  some  parta 
did  not  produce  pain  under  those  circumstances,  that  caused  others  to 
produce  pain.  The  reason  for  this  is  now  seen.  The  skin  produces 
pain  when  it  is  acted  upon  in  any  injurious  way,  because  it  is  the  out- 
post of  the  body  ;  but  why  should  the  parts  within,  be  painful  when 
pricked,  cut,  etc.  ?  The  skin  must  be  injured  before  they  can  be,  and  if 
it  give  warning  that  is  sufficiei,  „  But  the  tendons  are  exposed  to  the 
danger  of  being  twisted,  without  the  skin  being  injuriously  acted  on  ;  it 
cannot  give  warning  therefore.  Hence  the  tendons  do.  The  bones 
become  painful  as  soon  as  broken  or  diseased,  because  the  splints  and 
bandages  of  the  surgeon  cannot  be  applied  so  tightly  without  stopping 
the  circulation  of  the  blood  as  to  keep  the  bones  perfectly  quiet ;  the  person 
would  many  times  use  the  bones  before  they  had  fairly  recovered,  if 
they  were  not  painful.  When  they  are  not  so,  the  surgeon  is  usually 
under  the  necessity  of  making  them  so,  that  the  pain  may  assist  his 
splints  and  bandages,  loosely  applied,  in  keeping  the  bones  quiet  and  the 
person  from  using  them.  If  an  ulcer  be  upon  the  hand,  it  can  be  covered, 
and  allowed  rest,  but  if  disease  affect  the  lungs  or  heart,  they  must 
be  kept  in  action,  that  life  may  be  preserved.  If  they  were  painful, 
as  it  is  best  she  hand  should  be  under  like  circumstances,  the  pain 
would  wear  out  the  life  of  a  person,  much  before  it  now  terminates. 
When  pain  does  exist,  the  kind  of  pain  and  degree  of  it,  is  very  useful 
also  in  enabling  the  experienced  physician  to  determine  where  and  what 
the  disease  is.  Hence  the  difficulty  of  determining  with  accuracy  the 
disease  of  any  part,  when  it  is  not  the  cause  of  any  pain,  and  the  diseases 
of  children  who  cannot  describe  the  pain  felt ;  more  especially  when 
so  young  that  their  countenances  do  not  at  all  express  the  kind  of  pain 
they  are  suffering.  Thus  pain  is  a  great  blessing  ;  and  when  it  does 


SEC.  2.]  OBJECTS  PRODUCING  SENSATIONS.  119 

not  exist,  as  it  should,  instead  of  rejoicing,  the  physician  sets  himself  to 
produce  it,  by,  for  example,  rubbing  the  bones  together,  etc. 

It  is  to  be  noticed,  however,  that  sometimes,  as  far  as  we  can  now  see, 
pain  is  produced  without  a  good  result,  since  it  is  very  exhausting  and 
without  any  apparently  good  effect,  and  the  physician  finds  his  art  serves 
him  greatly,  by  enabling  him  to  minister  medicines,  which  shall  prevent 
the  painful  sensations,  without  interfering  with  the  curative  process  ;  for 
if  he  do  nothing  but  check  the  pain,  nature  will  be  able  to  cure  the 
disease,  when  otherwise  she  would  have  failed.  I  see,  however,  so  much 
perfection  in  the  human  system,  that  I  am  always  inclined  to  adopt  the 
expression  of  the  poet,  "  whatever  is,  is  right,"  and  to  think  the  reason 
why  I  cannot  see  it  so,  is  owing  to  my  short-sightedness,  and  fear  if  I 
should  change  any  thing,  I  should  be  hanging  the  "  pumpkin  on  the  oak," 
only  to  fall  upon  my  head  and  fell  me  to  the  ground. 

347.  Painful  or  unpleasant  sensations — quite  opposite  to 
pleasant  or  delightful  ones — tend  to  produce  melancholy,  to 
depress  the  spirits,  to  lower  health,  and  shorten  life  ;  to  ren- 
der the  disposition  fretful,  and  make  objects  repulsive  or  dis- 
agreeable. 

It  is  to  be  expected,  therefore,  that  the  sick  will  be  less  amiable  than 
when  well ;  and  allowance  must  be  accordingly  made.  Every  thing 
which  will  tend  to  cause  disagreeable  sensations,  must  be  avoided  ;  and 
the  attention  of  the  mind  so  occupied  with  sensations  which  will  not 
prove  hurtful,  that  painful  sensations  will  not  be  produced.  When  chil- 
dren are  sick,  this  is  especially  important.  And  sick  or  well,  we  should 
aveid  all  those  causes  which  produce  unpleasant  sensations. 


SECTION  2. — Objects  producing  Sensations. 

348.  An  object  is  any  thing  which  is  the  first  acting 
cause,  that  produces  a  sensation. 

This  object  may  be  external — as  when  ice  produces  a  sensation  of 
cold  ;  a  pin,  a  sensation  of  pricking  ;  a  rose,  a  sensation  of  smell,  &c., — • 
or  it  may  be  internal,  as  when  any  diseased  condition  of  any  part  of  the 
body  produces,  or  causes  to  be  produced,  any  sensation. 


120  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

349.  Different  objects  tend    to  produce   different   sen- 
sations. 

This  truth  hardly  needs  illustration ;  for  the  reason  why  objects  are 
called  different,  is  because  they  produce  different  sensations.  If  one 
object  were  precisely  like  another,  and  without  our  knowing  it  should 
be  put  in  the  place  the  other  occupied,  we  should  believe  it  was  the  same. 
There  are  twins  so  closely  resembling  each  other,  viz.,  produce  such 
similar  sensations,  that  people  do  not  distinguish  them,  except  they  are 
near  together,  viz.,  produce  sensations,  at  the  same  time,  when  if  the  sen- 
sations are  similar  in  all  other  respects,  they  are  different  in  this,  that 
the  objects  appear  to,  and  do,  occupy  different  places.  Thus  two  objects 
will  differ,  at  least  in  this,  that  they  cannot  occupy  the  same  place  at  the 
same  time. 

350.  Different  objects  produce  different  sensations  of  cer- 
tain kinds,  and  similar  sensations  of  certain  other  kinds. 

Thus  a  piece  of  ice  produces  a  sensation  of  coldness,  and  a  piece 
of  heated  iron  a  sensation  of  heat — in  which  respects  they  differ  ;  but  the 
ice  produces  a  sensation  of  weight,  and  the  iron  produces  a  sensation 
of  weight — in  which  respects  they  produce  similar  kinds  of  sensations. 
Sugar  produces  a  sensation  of  sweetness,  and  honey  produces  a  sensa- 
tion of  sweetness — in  which  respects  they  agree ;  but  sugar  is  a  solid 
and  honey  a  liquid,  in  which  respects  they  differ,  and  produce  corre- 
spondingly different  sensations.  Hence  objects  are  classed.  All  those 
which  produce  similar  sensations  of  any  kind,  in  respect  to  that  kind 
of  sensation,  are  classed  together,  and  called  by  the  same  name,  e.  g.,  all 
those  objects  which  produce  a  sensation  of  sweetness,  like  sugar,  are 
called  sweet :  all  those  which  cause  a  sensation  like  vinegar,  in  respect 
to  sourness,  are  called  sour ;  those  producing  sensations  in  respect  to 
coldness,  like  ice,  are  called  cold.  Thus  sugar,  molasses,  honey,  are 
called  sweet — and  in  this  respect  not  classed  with  vinegar ;  while  vinegar, 
honey,  molasses,  water,  &e.,  are  classed  together  in  certain  respects,  and 
called  liquids — while  sugar,  ice,  &c.,  are  classed  together  in  one  respect, 
and  called  solids.  Honey  and  molasses  fall  into  two  classes  together — 
they  are  sweet  and  they  are  liquids :  that  is,  they  produce  similar  sensa- 
tions of  two  different  kinds.  Thus, 

351.  The  more  kinds  of  similar  sensations  any  objects 
produce,  the  nearer  are  they  considered  to  be  of  the  same 
nature ;  till  at  last,  when  the  only  difference  of  sensations  is 


SEC.  2.]  OBJECTS  PRODUCING  SENSATIONS.  121 

in  respect  to  the  places  they  occupy,  they  are  considered 
to  be  of  the  same  identical  nature. 

352.  The  same  objects  may  be  said  to  produce  different 
sensations  under  different  circumstances. 

But  this  is  not  strictly  correct ;  for  if  it  be  said,  that  boiling  water 
produces  a  different  sensation  from  water  of  a  low  temperature — it  is  not, 
properly  speaking,  the  water  in  either  case,  but  the  caloric  (commonly 
called  the  heat)  which  produces  the  sensation.  Thus  when  any  different 
sensation  is  produced  by  an  object,  it  would  be  proper  to  speak  of  it  as  a 
new  object ;  but  for  present  purposes,  it  will  confuse  the  mind  less  to 
adopt  the  common  expression — and  draw  the  mind  to  the  next  very  im- 
portant proposition,  viz. 

353.  That  every  object  has  a  tendency  to  produce,  under 
similar  circumstances,  a  similar  effect. 

This  must  be  so,  or  we  should  be  unable  to  place  any  confidence  in 
sensations  ;  they  would  be  of  no  use  to  us.  But  when  we  feel  a  certain 
sensation,  we  say  without  hesitation,  it  is  produced  by  sugar,  by  a  rose, 
by  ice,  etc.  If  it  be  argued  that  the  same  objects  do  really  produce,  or 
cause  to  be  produced,  different  sensations,  it  is  granted.  Indeed,  that  ia 
what  I  wish  to  prove,  and  at  the  same  time,  that  this  is  not  owing  to 
any  change  in  the  nature  of  the  objects  acting,  but  in  the  organs  of  sen- 
sation acted  on.  If  an  article  produce  a  different  sensation  from  what  is 
usual,  for  instance,  if  it  taste  differently,  it  is  easily  proved  that  this  ia 
not  on  account  of  any  change  which  has  taken  place  in  the  article,  for 
other  persons  will  say  they  do  not  notice  any  change  in  the  sensation  it 
produces.  If  wine  be  tasted  after  sweet  things  have  been  eaten,  it  will 
taste  flat  or  insipid.  If  it  be  tasted  after  cheese,  its  flavor  is  said  to  be 
improved.  Now  the  wine  cannot  have  changed  its  nature  while  a 
person  has  been  eating  a  piece  of  cheese,  because,  to  those  who  have  not 
eaten  any  its  taste  is  not  altered.  Sensations  caused  by  an  object  are 
oftentimes  at  first  unpleasant,  but  after  frequent  repetitions,  the  sensation 
is  different  and  pleasant.  The  same  world  is  around  all :  to  one  it  ia 
full  of  beauty — every  sight  is  charming — every  sound  melodious ;  to 
another  it  is  so  dull  and  prosy  as  to  be  hardly  worth  living  in — it  ia 
fruitful  in  nothing  but  faults — every  object  creates  ugly  sensations.  Why 
the  difference  1  It  cannot  be  owing  to  the  different  action  of  the  same 
objects  upon  persons,  but  to  the  action  of  objects  upon  different  persons. 
The  things  are  the  same,  acting  under  similar  circumstances — our  con- 


122  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

Btitutions  must  be  different.  When,  therefore,  an  object  is  called  un- 
pleasant it  is  not  using  language  correctly.  It  may  produce  pleasant 
sensations  in  another  constitution.  By  such  language  we  attribute  to  an 
'inanimate  thing,  an  ill  disposition  and  a  versatility  of  character  not 
belonging  to  it. 

354.  It  should  be  inferred,  then,  that,  as  beauty  is  in  the 
eye,  the  music  in  the  ear  mental  as  well  as  physical,  as  the 
nature  of  things  is  inflexible  and  will  not  adapt  itself  to  us, 
and  as  by  the  power  of  the  Creator  it  has  been  made  right, 
and  as  we  are  susceptible  of  change  and  our  organs  of 
adaptation,  if  the  sensations  we  experience  are  agreeable 
all  change  should  be  prevented ;  but  if  in  a  world  so  perfect, 
so  lovely,  gloomy  and  disagreeable  sensations  are  felt,  a 
change  should  be  wrought  in  the  system. 

To  do  this  a  person  may  feel  encouraged  by  his  own  and  others'  ex- 
perience of  the  facility  with  which  changes  may  be  produced.  If  it  be 
desirable  to  know  what  course  to  adopt,  it  may  be  learned  by  giving 
attention  to  the  organs  of  sensation,  and  the  condition  of  them,  neces- 
sary to  produce  pleasant  or  unpleasant  sensations.  By  the  knowledge 
thus  gained,  he  will  be  able  to  produce  a  state  of  proper  relation  between 
his  organs  and  the  objects  of  nature,  which  will  result  in  delightful,  or  if 
painful,  yet  profitable  sensations. 


SECTION  3. — The.  Organs  of  Sense. 

355.  These  are  those  parts  of  the  body  in  which  the 
nerves   of  sensation   commence,   and   by  means  of  which 
objects   are  caused  to  act  in  a  proper   manner   upon   the 
nerves. 

The  most  important  part  of  any  organ  of  sense  is,  therefore,  the 
commencing  point  of  the  nerve. 

356.  These  organs  of  sense  are  also  sometimes  the  objects 
which  produce  the  impression  upon  the  nerve. 

The  skin  is  an  organ  of  sense  j  when  it  is  diseased  it,  like  an  object 


SEC.  3.]  ORGANS  OF  SENSE.  123  % 

without  any  thing  acting  on  it,  acts  on  the  nerve.  In  the  same  manner 
other  parts  of  the  body  produce  effects  upon  the  nerves  commencing  in 
them. 

357.  Not  only  is  every  part  of  the  body  an  object  produc- 
ing sensations,  but  it  is  also  an  organ  of  sense,  as  I  presume 
there  is  not  any  part  of  the  body  in  which  nerves  do  not 
commence. 

358.  It  is  also  evident  that  within  the  body,  the  parts 
producing   effects  on  the  nerves  come   directly  in  contact 
with  the  nerves,  and  act  upon  them  without  any  thing  inter- 
vening. 

As  in  case  of  diseases  of  the  skin,  the  part  diseased,  which  in  this 
case  is  the  object,  is  directly  about  and  upon  the  nerves  through  which 
an  effect  is  produced  on  the  brain. 

359.  But  in  case  of  those  nerves  through  which  external 
objects  cause  effects  to  be  produced  on  the  mind,  it  would 
not  be  allowable  to  have  the  objects  act  directly,  as  the  nerves 
would  be  injured  by  exposure.     Such  nerves  have,  there- 
fore, been  covered. 

As  in  case  of  the  nerves  commencing  in  the  skin,  they  will  be  found 
a  short  distance  below  the  outer  surface,  as  in  Fig.  50.  Also  in  case  of 
the  nerve  of  taste,  commencing  in  the  mouth,  and  in  case  of  the  nerve 
of  smell,  commencing  in  the  nose,  the  points  of  the  nerves  will  be  found 
just  below  the  surface. 

360.  In  case  of  the  eye  and  ear,  it  is  necessary  that  the 
objects  producing  the  impression  upon  the  nerve  should  be 
acted  upon  in  a  peculiar  way,  that  effects  or  impressions 
may  result.     Here,  therefore,  the  nerve  is  found  at  the  bot- 
tom of  an  apparatus  adapted  to  fulfil  its  duties  perfectly. 

361.  It  is  evident,  therefore,  that  there  are  several  kinds 
of  organs  of  sense.     Those  parts  of  the  body  through  which 
any  kind  of  sensation  is  produced,  and  which  cannot  be  pro- 
duced by  or  through  any  other  part,  are  considered  to  belong 
to  the  same  class.     We  have  six  classes :  the  ear,  the  eye, 
the  nose,  the  mouth,  the  muscles,  and  to  avoid  too  much  sub- 


124  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

Fig.  50. 


Fig.  50. — Represents  one  half  of  the  cerebrum,  A,  and  cerebellum,  B,  and  medulla 
oblongata,  C  An  enlargement  called  a  ganglion  is  seen  at  D.  1  is  a  nerve  represented 
as  terminating  in  a,  b,  c,  rf,  e,  just  below  a  at  the  surface  of  b,  in  the  little  eminences 
or  papillae  there  found,  a,  6,  c,  d,  e,  is  an  ideal  representation  of  an  organ  of  sens*, 
and  whatever  acts  upon  the  surface  of  a  will  affect  the.  commencement  of  the  nerves. 
1,  2  represents  nerves  commencing  in  any  part  of  the  body  below  the  surface.  3  re- 
presents a  plexus  by  which  it  is  seen  that  disease  may  exist  at  certain  parts  and  not 
affect  all  the  fibres  passing  between  any  point  and  the  brain.  4  represents  the  sec- 
tion of  certain  nerves.  If  the  cut  end  at  4  be  touched,  a  sensation  will  be  supposed 
to  be  produced  where  the  ends  of  4  naturally  are. 


division,  all  the  other  parts  of  the  body  are  grouped  together 
and  called  organs  of  common  feeling. 

Though  some  distinguish  the  skin  as  the  organ  of  touch,  and  all 
other  organs  as  organs  of  common  feeling  or  sensation,  others  make 


SEC.  3.]  ORGANS  OF  SENSE.  125 

other  subdivisions  still,  calling  the  stomach  and  throat  organs  of  the 
sense  of  nausea  ;  certain  parts  through  which  tickling,  etc.,  are  produced, 
organs  of  the  sense  of  tickling. 

A.    The   Organs  of  the   Sense   of  Common   Sensation,  or 
Common  Feeling. 

362.  1st.   The  Skin.      This  includes  the  lining  of  the 
eyes,  nose,  and  mouth,  and  in  a  certain  sense  the  lining  of 
the  stomach,  and  the  whole  or  a  part  of  the  remaining  portion 
of  the  digestive  canal.     It  is  distinguished  as  the  organ  of 
touch,  and  may  be  considered  as  including  all  those  parts  of 
the  body  which  will  produce  the   sensation  of  contact  when 
merely  acted  on  by  an  object  neither  hot  nor  cold,  nor  in  any 
way  injurious. 

The  sensation  referred  to  is  that  indefinite  sensation,  not  pleasurable 
or  unpleasant,  which  merely  informs  of  the  presence  of  an  object 
in  contact  with,  or  touching  us,  but  gives  no  other  definite  idea.  It  is 
such  as  is  produced  by  a  tasteless  substance  in  the  mouth,  or  by  food  as 
it  is  being  swallowed.  It  is  entirely  different  from  the  sensation  produced 
if  the  food  be  swallowed  "  the  wrong  way,"  and  pass  into  the  wind-pipe  ; 
there  is  then  a  tickling,  an  unpleasant  sensation.  Some  have  supposed 
that  the  sensation  of  contact  or  touch,  was  produced  by  the  difference 
in  temperature,  of  the  object  and  the  surface  touched  ;  but  the  saliva  in 
the  mouth  produces  a  sensation  of  touch,  and  if  an  object  be  of  the  same 
temperature  with  the  body  and  brought  ever  so  gently  in  contact,  a  sen- 
sation will  yet  be  instantly  perceived. 

363.  The  skin,  as  an  organ  of  sense,  is  of  use  merely  in 
affording  to  the  nerves  a  proper  commencing  place,  and  in 
protecting  them  from  exposure. 

364.  For  this  purpose  a  thin  layer  of  skin,  and  but  a  thin 
layer,  as  in  Fig.  50,  is  overlaid  upon  the  nerves,  while  the 
layers  below  serve  as  a  support  to  the  nerves,  and  allow  of 
their  proper  arrangement. 

How  the  nerves  commence,  is  not  known.  Some  think  that  they 
commence  by  loops,  while  others  think  they  commence  by  points. 
There  is,  doubtless,  an  arrangement  of  loops  to  be  seen,  but  it  seems 


126  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

to  me  these  are  not  the  commencements  of  the  nerves,  which  I  am  in- 
clined to  think  commence  by  points,  and  form  the  loops  by  uniting  with 
each  other  in  a  plexiform  manner.  I  shall  therefore  speak  of  the  nerves 
as  commencing  by  points,  as  there  is  a  particular  point  of  the  nerve 
where  it  is  acted  on,  where  the  impression  is  produced,  and  where  the 
mind  always  considers  that  the  impression  is  made.  For  instance,  if 
the  nerve  connecting  between  any  point  of  the  skin  and  the  brain  be 
pricked,  at  any  place  between  the  skin  and  brain,  we  are  so  constituted 
as  to  believe  the  point  of  the  nerve  in  the  skin  has  been  pricked.  If  a 
man's  arm  have  been  removed,  and  the  nerves  which  commenced  ia 
the  hand  be  pricked  at  the  stump,  it  will  seem  to  him  that  the  hand  is 
pricked,  though  the  hand  has  been  lost  for  a  long  time.  If  the  nerves 
be  acted  on  by  cold,  it  will  seem  to  him  that  his  hand  is  cold.  Thus 
also  if  disease  affect  any  nerve  in  any  part  of  its  course,  and  cause  pain- 
ful sensations,  we  are  so  constituted  that  the  mind  believes  the  disease 
exists  where  the  nerve  commences  but  on  farther  examination  no  dis- 
ease is  found  at  that  place,  and  the  experienced  physician  knows  ;  as  a 
general  thing,  that  disease  exists  at  some  point  in  the  course  of  the  nerves 
connecting  that  part  with  the  brain.  Thus,  if  the  foot  be  cold,  no  mat- 
ter how  warm  the  central  parts  of  the  body  are  in  which  the  interme- 
diate portion  of  the  nerve  is  situated,  the  nerve  is  so  made,  that,  if  healthy, 
it  acts  on  the  brain,  or  on  the  mind,  only  according  to  the  impression 
produced  on  its  commencing  point  in  the  foot,  and  receives  no  impression 
from  the  warm  parts,  acting  through  its  sides.  This  is  to  me  one  of  the 
most  wonderful  phenomena  to  be  observed  in  the  whole  economy  of  the 
system :  but  to  return  to  the  skin. 

365.  That  the  nerves  may  be   properly  acted  upon,  the 
under  layer  of  the  skin  is  formed  into  a  great  number  of  em- 
inences called  papillae  (Fig.  51).      They  may  be  seen  at 
the  ends  of  the  fingers,  in  rows,  beneath  the  delicate  layer 
which  protects  them.     In  those  places  they  are  very  near 
each  other,  in  other  places  they  are  more  remote.     In  these 
papillae  the  nerves  commence. 

366.  The  more  numerous  these  are,  the  more  acute  is  the 
power  of  producing  sensation  in  any  part,  and  the  more  per- 
fectly  can  objects  be  distinguished. 

Any  one  can  try  the  experiment  mentioned,  by  Weber  I  think,  of 


SEC.  3.]  ORGANS  OF  SENSS.  127 

r.51. 


Fig.  51.— 1,  The  cuticle.  2,  The  rete-mucosun.  3,  Two  of  the  papillse.  4,  The  deep 
layer,  or  dermis— true  skin.  5,  Fat  cells,  magnified  very  much.  6,  Perspiratory  gland 
with  spiral  outlet.  7,  Another  perspiratory  gland  with  a  straight  tube  as  seen  in  the 
scalp.  8,  The  roots  of  two  hairs  inclosed  in  their  sacs  or  follicles.  At  9,  is  seen  th« 
short  tube  of  several  cryptae,  forming  a  gland,  and  which  form  the  oily  or  sebaceous 
substance  which  oozes  upon  the  surface  of  the  skin,  to  preserve  it  in  a  good  condition. 

immersing  the  finger,  and  then  the  hand,  in  very  warm  water.  The  heat  of 
the  water  will  become  apparently  more  intense,  the  greater  the  surface  upon 
which  it  acts.  The  heat  of  the  water  does  not,  however,  increase,  but  it 
seems  the  sensations  become  more  powerful  the  greater  the  number  of 
nerves  acted  upon  at  the  same  time.  Thus  when  the  papillae  are  thick,  the 
same  object  will  act  on  a  greater  number  of  nerves,  than  when  the  num- 
ber of  the  papillae  is  less.  It  has  been  found  also  that  if  the  points  of  two 
needles,  at  certain  distances,  touch  the  skin  of  one  part  of  the  body,  e.  g. 
the  ends  of  thr  fingers,  they  will  be  distinguished  as  two  things,  while, 
if  they  touch  certain  other  parts,  they  will  appear  as  but  one  thing,  and 
the  distance  of  the  points  from  each  other  must  be  increased,  that  they 
may  appear  as  two  things. 

367.  The  structure  of  the  skin  differs  in  its  protective 
character,  in  different  parts  of  the  body. 

Wherever,  by  use,  it  is  frequently  pressed  upon,  its  external  layer 


128  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  H. 

becomes  tnick,  callous,  almost  homy  at  times,  as  upon  the  soles  of  the 
feet,  in  the  palms  of  the  hands,  etc. 

368.  lu  other  respects,  as  an  organ  of  sense,  it  does  not 
appear  to  differ  throughout  its  entire  extent.  Yet  through 
different  parts  of  it,  the  same  causes  produce  different  effects, 
which  seem,  therefore,  to  be  owing  not  to  any  difference  in 
the  structure  of  the  skin,  but  a  difference  in  the  constitution 
of  the  parts,  connecting  between  the  skin  and  mind. 

Through  one  part  of  the  skin,  the  sensation  of  tickling  can  be  pro- 
duced, through  another  part  it  cannot.  A  similar  effect  is  produced  upon 
the  skin,  in  one  case,  as  in  the  other,  bat  a  different  effect  upon  the 
nerves,  because  they  are  differently  made.  If  the  odor  of  the  rose  be 
drawn  through  the  nose,  it  produces  a  sensation,  but  if  it  be  drawn 
through  the  mouth,  when  the  nose  is  closed,  it  does  not  produce  a  sen- 
sation. The  skin,  lining  these  parts,  does  not  seem  to  materially  differ 
in  its  structure.  The  reason  for  the  difference  must,  therefore,  be  in  the 
constitution  of  the  nerves,  connecting  these  parts  with  the  mind,  as  will 
be  hereafter  substantiated.  It  is  important  to  notice  this  point,  viz.,  the 
proof  that  the  nerves  are  differently  constituted.  I  will  therefore  mention 
one  more  illustration.  Different  parts  of  the  body,  are  of  different  tem- 
peratures, naturally.  The  feet  are  naturally  the  coolest  parts  of  the  body, 
the  head  much  warmer,  but  not  as  warm  as  the  heart,  lungs,  etc.  The 
hands  are  warmer  than  the  feet ;  hence  if  the  hand  touch  the  foot  when 
both,  in  themselves  considered,  are  perfectly  comfortable,  the  foot  will 
feel  cool  to  the  hand,  and  the  hand  feel  warm  to  the  foot ;  because  the 
natural  heat  of  the  hand,  acting  upon  the  nerves  of  the  foot,  is  too  much 
for  them,  and  vice  versa.  The  comparative  warmth  or  coldness  natu- 
ral to  any  part,  depends  on  its  distance  from  the  heart  and  the  quantity 
of  blood  it  receives,  as  will  hereafter  be  proved.  The  nerves  therefore 
commencing  in  any  part,  must  be  acted  on  by  a  degree  of  temperature, 
a  shade  different  from  that  acting  on  the  nerves  of  any  other  part,  and 
fet  they  all  produce  one  sensation — a  sensation  of  comfort.  Is  it  not 
astonishing  that  the  temperature  acting  on  the  nerves  of  the  foot,  should 
produce  the  same  sensation  of  comfort  as  the  different  temperature  act- 
ing on  the  nerves  of  the  hand  ?  And  if  the  temperature  of  the  foot 
rises  to  the  temperature  of  the  hand,  and  which  through  the  nerves  of 
the  hand  produces  a  feeling  of  comfort,  it  should,  through  the  nerves  of 
the  foot,  produce  an  uncomfortable  sensation,  of  too  much  heat.  There- 


SEC.  3.]  ORGANS  OP  SENSE.  129 

fore  the  nerves  of  the  two  parts  must  be  differently  constituted  ;  and  the 
millions  upon  millions  of  nerves  connecting  the  various  points  of  the 
surface  of  the  body  with  the  mind,  must  be  constituted  with  almost  as 
much  variety  as  there  are  nerves,  and  in  such  manner  that  each  nerve 
will  be  acted  upon  so  as  to  produce  an  agreeable  sensation,  by  the 
natural  temperature  of  the  part  in  which  it  commences,  and  produce 
a  disagreeable  sensation  when  the  slightest  change  in  this  natural  tem- 
perature takes  place.  It  is  a  wonderful  thing  that  we  are  made  as 
we  are,  and  almost  as  wonderful  that  we  know  so  little  how  we  are 
made.  When  the  poet  sung, "  It  is  a  harp  of  a  thousand  strings,"  he 
had  but  a  feeble  conception  of  his  subject.  Indeed,  the  eloquence  of 
man  must  be  dumb,  when  the  perfection  of  the  Creator's  works  is 
before  us. 

369.  The  uses  of  the  skin,  as  an  organ  of  sense,  may  be 
considered  under  three  heads.     In  the  first  place : 

370.  It  may  be  considered  as  producing  negative  sensa- 
tions ;  that  is,  those  which  cause  neither  pleasure  nor  pain. 

It  produces  such  sensations  when  any  thing  comes  in  contact  with 
it, if  the  thing  be  neither  profitable  nor  harmful.  There  is  no  reason  why,  in 
such  a  case,  pleasure  or  pain  should  be  produced ;  it  will  do  us  no  harm 
if  the  object  touch  us,  it  will  do  us  no  particular  good.  The  instant  it 
becomes  harmful,  the  skin  produces  an  additional  sensation  of  pain  ;  and 
when  necessary  for  our  welfare,  it  produces  a  sensation  of  pleasure. 
This  negative  sensation,  is  called  the  sensation  of  touch.  Some  suppose 
sensations  of  touch  inform  the  mind  of  the  solidity  of  an  object  by  the 
depth  to  which  the  object  acts ;  that  is  to  say,  if  the  finger  be  pressed 
upon  any  thing,  which  is  soft  or  yielding,  it  will  produce  an  effect  only 
on  the  nerves,  commencing  near  the  surface — if  the  object  be  more  solid, 
it  will  act  on  nerves  commencing  deeper.  Some  also  think,  that  the 
form  and  size  of  many  things  are  determined  by  the  number  and  position 
of  the  nerves  through  which  the  sensation  of  touch  is  produced  ;  that 
is,  if  an  object  one  inch  long  be  touched,  it  will  affect  only  half  as  many 
nerves  as  if  it  be  two  inches  long.  Some  think  the  smoothness  of  an 
article  is  determined  by  similar  sensations ;  as,  if  an  article  be  rough,  it 
touches  only  a  few  nerves,  the  commencements  of  which  are  not  near 
each  other — while,  if  the  article  be  smooth,  each  nerve  is  acted  on.  But 
it  would  seem,  these  things  are  determined  partly,  if  not  wholly,  by 
muscular  sensations,  as  hereafter  shown. 

6* 


130  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

371.  Second.    It  may  be  considered  as  producing  posi- 
live  sensations  of  pleasure  or  pain. 

Its  duty  is,  to  produce  such  sensations,  especially  when  acted  upon 
by  prpper  or  improper  temperatures.  Preserving  a  certain  temperature 
is  so  important  to  health,  that  it  is  rewarded  with  the  most  pleasurable 
sensations  ;  while  the  slightest  deviation  is  noticed  by  corresponding  un- 
pleasant sensations.  And  as  the  whole  duty  of  guarding  the  system, 
in  this  respect,  depends  on  this  organ  of  sense,  it  might  pre-eminently  be 
called,  the  organ  of  the  sense  of  temperatures.  How  much  it  adds  to 
the  enjoyments  of  life,  every  one  has  appreciated  when  walking  in  the 
field  or  resting  in  the  shade,  quite  satisfied  with  the  delicious  sensations 
of  a  summer's  day.  Still  more  was  it  our  friend,  if  perspiring  and  ex- 
hausted, we  thoughtlessly  threw  ourselves  down  where  the  temperature 
of  the  body  was  reduced  too  rapidly.  The  cold  chill  that  ran  through 
the  frame,  aroused  us  to  safety.  All  injuries  from  which  the  skin  suffers, 
will  excite  it  to  cause  unpleasant  sensations.  It  is  thus  our  never  sleep- 
ing guard. 

372.  Third.    It  may  be  considered  as  the  organ  of  the 
sense  of  tickling,  and  many  other  such  sensations  which  are 
worthy  of  merely  a  notice. 

The  particular  characteristics  of  the  skin,  as  an  organ  of  sense  in  the 
mouth  and  nose,  will  be  mentioned  hereafter. 

373.  To  fit  the  skin  for  fulfilling  its  duties  as  an  organ 
of  sense ;  in  the  first  place,  it  will  be  necessary  that  the  ex- 
ternal protecting  layer,  called  the  cuticle,  scarf-skin,  epider- 
mis, &c.,  be  flexible,  delicate,  and  as  thin  as  the  position  it 
occupies  will  permit. 

374.  To  preserve  these  good  qualities,  it  is  constantly 
lubricated  with   an  oily  fluid,  formed   in   little  pouches  or 
bags,   called  cryptae  or  follicles  (Fig.  51),  and  poured  out 
upon  the  surface  through  their  open  mouths. 

As  this  fluid  is  of  an  oily  nature  it  must  be  constantly  removed  from 
the  skin,  otherwise  a  collection  of  it  will  take  place,  which  becoming 
gummy,  will  prevent  the  existence  of  that  delicacy  which  it  is  intended 
to  preserve.  That  it  should  be  oily,  is  evident  enough,  as  it  was  neces- 
sary it  should  protect  the  skin  from  the  action  of  water  and  other  things; 


SEC.  3.]  ORGANS  OF  SENSE.  131 

which  are  decidedly  injurious,  as  is  seen  when  the  oil  has  been  removed 
from  the  skin,  not  only,  but  drawn  out  from  it  by  the  continued  applica- 
tion of  hot  water — especially  if  assisted  by  soap,  e.  g.  the  hands  of  the 
washerwoman.  The  skin  is  not  then  delicate  and  well  adapted  to  act 
as  the  organ  of  touch.  A  proper  application  of  water,  perhaps,  assisted 
by  soap,  is  to  be  recommended  ;  not  such  that  the  oil  shall  be  exhausted 
from  the  skin,  but  merely  rerrroved  from  its  surface.  To  assist  this,  the 
skin  may  be  vigorously  rubbed  with  a  towel,  more  or  less  harsh,  as  the 
case  may  require,  and  as  may  "  feel  comfortable." 

375.  The  fluid  being  formed  from  the  blood,  a  plentiful 
supply  of  this  is  necessary. 

This  is  obtained  by  general  exercise,  for  that  action  of  the  muscles 
which  urges  the  blood  along  through  themselves,  assists  in  circulating  it 
through  the  skin ;  by  briskly  rubbing  the  skin,  for  the  efficacy  of  this 
may  at  any  time  be  seen,  the  skin  glowing  with  the  life-giving  blood 
that  is  brought  into  it  by  rubbing  any  part ;  and  by  proper  clothing,  for 
without  this,  the  blood  cannot  be  long  retained  in  the  skin. 

376.  To  fit  the   skin  for   fulfilling  its  duties;   in  the 
second  place,  it  will  be  necessary  to  preserve  a  free  circula- 
tion of  blood,  through  the  deep  layers  of  the  skin ;  for  on  the 
reception  of  blood  in  ample  quantities,  depends  the  life  and 
energy  of  the  nerves. 

If  a  person  be  exposed  to  the  cold,  which  contracts  the  bloodvessels 
and  shuts  out  the  blood,  the  part  affected  becomes  numb.  On  the  other 
hand,  if  the  bloodvessels  are  overloaded  with  blood,  and  its  circulation 
thus  checked,  sensations  are  equally  indistinct  and  vague.  The  same 
means  which  will  supply  blood  for  the  formation  of  the  oily  fluid,  will 
supply  it  for  the  good  of  the  nerves  at  the  same  time.  This  illustrates 
what  will  often  be  noticed,  that  what  is  for  the  good  of  a  part,  in  one  res- 
pect, is  good  for  it  in  all,  and  never  injurious. 

377.  2d.  We  may  now  consider  the  remaining  organs  of 
common  feeling.      All  parts  of  the  body  are  thus  grouped 
together,  not  because  they  produce  similar  sensations,  partic- 
ularly speaking,  but  because  the  sensations  they  produce  are 
for  the  same  general  purpose,  viz.,  to  inform  the  mind  of  the 
good  or  bad  condition  of  any  part  of  the  body, — of  a  good 


132  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

condition,  by  producing  pleasurable  sensations — of  a  bad  con- 
dition,  by  painful  or  unpleasant  sensations  ;  and  because  the 
arrangement  for  acting  on  the  nerves  is  similar  in  all  these 
parts,  viz,,  the  parts  or  organs  act  directly  on  the  nerves, 
which  commence  in  them. 

If  each  part  which  produces  peculiar  sensations  were  considered  as 
an  organ  of  sense,  this  group  would  be  very  much  subdivided.  The  sen- 
sations caused  by  the  windpipe,  when  any  thing  falls  into  it,  are  dissimi- 
lar to  any  others,  and  the  lining  of  the  windpipe  might  be  distinguished  as 
an  organ  of  sense.  A  decayed  tooth  produces  a  peculiar  pain,  and  that 
might  be  called  an  organ  of  sense  ;  and  so  every  other  part,  which  con- 
stantly produces  peculiar  sensations,  might  be  looked  upon  as  an  organ 
of  sensation  ;  but  this  subdivision  would  be  useless.  By  nature  or  by 
experience  we  learn  the  meaning  of  the  various  sensations  ;  that  is,  where 
and  how  they  are  caused  ;  and  are  thus  able  to  give  attention  to  the 
cause  of  the  evil,  and  what  is  still  more  important,  to  the  prevention  of 
its  re-occurrence. 

B.  The  Muscular  Sense. 

378.  Before  the  time  of  Sir  Charles  Bell,  the  rnusclea 
were  not  considered  as  organs  of  a  particular  sense,  but  were 
included  among  the  organs  of  common  feeling.      He  called 
attention  to  the  importance  of  distinguishing  the  muscles  as 
organs  of  a  peculiar  sense,  and  was  the  means  of  exalting 
them  to  their  proper  station. 

379.  The  nerves  which  connect  between  the  muscles  and 
the  brain  are  acted  on  immediately  by  the  contracting  mus- 
cle, different  sensations  being  produced  by  different  degrees 
of  contraction. 

Thus,  if  the  muscle  contract  or  shorten  one  inch,  one  sensation  will 
be  produced ;  if  the  muscle  contract  two  inches,  or  more,  or  less,  a  dif- 
ferent sensation  will  be  produced.  Hence 

380.  The  mind  knows  the  degree  of  contraction  of  the 
muscle,  by  the  sensation  produced. 

And  as  the  contraction  of  the  muscle  produces  correspondent  motion 
of  some  part  of  the  body, 


SEC.  3.]  ORGANS  OF  SENSE.  133 

381.  The  mind  knows  the  amount  of  motion  produced, 
and  also  the  kind,  by  the  sensations  produced. 

Thus  the  mind  is  able  to  guide  the  motions  of  all  parts  of  the  body ; 
e.  g.,  if  a  person  wish  to  raise  the  hand  in  a  straight  line,  the  mind,  from 
previous  experience,  knows  the  sensations  the  muscles  should  cause,  when 
contracting  in  such  a  manner  as  to  produce  the  desired  motion  ;  as  soon, 
therefore,  as  any  other  sensation  is  felt,  the  mind  checks  the  action  of  the 
muscle  or  muscles  producing  the  wrong  sensation,  and  causes  the  proper 
contraction  to  take  place,  thus  regulating  the  motion. 

382.  Another  kind  of  sensation  is  at  the  same  time  pro- 
duced, viz.,  a  pleasurable  sensation,  of  a  character  peculiar 
to  the  proper  action  of  the  muscles. 

The  reason  for  this  is  quite  clear :  the  action  of  the  muscles  is  so  es- 
sential to  man,  that  it  is  important  they  be  always  kept  in  a  healthy  con- 
n^on.  This  cannot  be  without  exercise.  If  it  be  not  necessary  to  use 
them  to-day,  it  may  be  to-morrow,  or  the  next  day,  or  the  next.  It  is 
essential  that  they  be  exercised  to-day,  and  every  day.  A  pleasurable 
sensation  has  been  therefore  wisely  caused  to  attend  the  exercise  of  the 
muscles,  as  a  reward,  and  also 

383.  Another   sensation  of   an  unpleasant  character  is 
produced,  when  the  muscle  is  not  exercised,  to  punish  us  for 
not  doing  our  duty. 

384.  Another  sensation  is  produced,  when  the  muscle  has 
been  over-exercised.     This  is  to  induce  us  to  allow  it  repose, 
that  it  may  recover  that  strength,  healthy  condition,  and  per- 
fection,  it  has  in  a  measure  lost  by  action. 

Some  suppose  that  rest,  after  muscular  action,  is  necessary,  rather  for 
allowing  the  nervous  system,  than  the  muscular,  to  regain  vigor.  But  as 
the  sensation  of  weariness  or  fatigue  is  felt  only  in  the  muscles  exercised, 
the  supposition  seems  to  be  gratuitous.  When  the  nervous  system  is  ex- 
hausted, the  person  is  apt  to  express  himself — "  I  feel  tired  all  over." 

385.  Another  sensation  is  felt  when  repose  is  given  to 
the  muscle.      This  is  of  a  pleasurable  character,  and  is  to 
reward  a  person  for  care,  and  to  induce  it  on  other  similar 
occasions. 


134  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  H. 

386.  Still  another  sensation  is  felt,  when  the  muscle  is 
cut,  bruised,  &c.,  or  diseased. 

This  sensation  seems  to  be  of  the  same  character  as  those  produced 
by  the  organs  of  common  feeling  or  sensation ;  and  in  this  respect  the 
muscles  might  be  included  in  the  same  category  with  them. 

387.  The  sensations  produced  by  the  action  of  the  mus- 
cles, enable  us  to  determine  the  hardness  of  an  object,  its 
form,  its  size,  and  to  a  degree,  if  not  wholly,  its  smooth- 
ness, &c. 

For  if  the  muscle  be  contracted  to  a  given  degree,  and  motion  is  yet 
resisted,  the  object  would  be  considered  correspondingly  solid  ;  e.  g.,  if  the 
finger  be  placed  upon  dough,  and  the  muscles  of  the  arm  which  move  the 
finger  be  contracted  to  a  certain  degree,  motion  of  the  finger  is  produced  ; 
while,  if  the  finger  be  placed  upon  the  table,  no  motion  of  the  finger 
takes  place,  with  a  similar  contraction  of  the  muscles.  The  table  is  then 
called  harder  than  the  dough.  The  form  of  an  object  is  determined  by 
the  contraction  of  the  muscles  as  the  hand  is  laid  upon  its  surface.  For 
instance,  if  the  musc.es  contract  so  as  to  draw  the  fingers  perpendicular 
with  the  palm  of  the  hand,  the  object  is  considered  to  have  a  square 
edge.  If  the  muscles  contract,  as  when  the  fingers  grasp  a  ball,  the  ob- 
ject is  considered  spherical.  Of  course,  in  this  case,  the  sensations  pro- 
duced by  touch  assist  and  are  essential ;  for  the  form  of  an  object  is  de- 
termined by  the  contractions  of  the  muscles  necessary  to  cause  its  surface 
to  be  touched  by  the  body — more  commonly  by  the  hand  or  fingers.  In 
the  same  way,  the  size  is  determined.  For  as  a  greater  or  less  contrac- 
tion of  the  muscles  of  the  arm  is  necessary,  to  sweep  the  hand  over  the 
object,  so  is  the  object  regarded  as  larger  or  smallej: ;  and  as  the  muscles 
meet  with  more  or  less  opposition,  so  is  the  object  regarded  as  smooth 
or  rough. 

C.    The  Sense  of  Taste. 

388.  The  tongue  and  back  part  of  the  sides  of  the  mouth 
are  the  organs  of  the  sense  of  taste. 

The  skin  lining  the  entire  mouth  is  at  the  same  time  the  organ  of 
the  sense  of  touch  and  common  feeling.  A  bit  of  sugar  placed  any 
where  in  the  mouth  produces  a  sensation  of  touch,  but  only  in  certain 
parts,  the  sensation  of  taste.  The  sensation  of  taste  is  not  caused 
through  the  same  nerves,  therefore,  as  the  sensation  of  touch ;  this  is 


SEC.  3.]  ORGANS  OF  SENSE.  135 

also  proved  by  the  effects  of  disease,  which  sometimes  takes  away  the 
power  of  tasting  without  affecting  the  power  of  touch,  and  vice  versa. 
That  is,  by  disease  a  person  is  unable  to  taste  sugar  placed  upon  the 
tongue,  though  the  sugar  produces  the  sensation  of  touch  the  same  aa 
ever,  or  in  other  cases  he  tastes  the  sugar  when  it  produces  no  sensation 
of  touch. 

389.  The  organs  of  taste  may  be  considered  as  double, 
the  central  line  on  the  surface  accurately  dividing  the  tongue 
into  two  tongues,  so  far  as  tasting  is  concerned. 

This  is  proved  by  dissection,  and  by  disease,  which  sometimes  unfits 
the  nerves  of  one  side  for  performing  their  duty. 

390.  The  nerves  of  taste  commence  in  the  lining  of  the 
mouth  in  the  same  manner  as  the  nerves  of  touch.     The 
papillae  in  which  they  commence  are  much  more  numerous 
at  the  tip  of  the  tongue  than  elsewhere,  hence  that  is  the 
part  which  produces  the  most  lively  sensations. 

It  is  proper  it  should  be  so,  for  that  part  can  be  thrust  from  the  mouth, 
and  with  it  articles  can  be  tasted  before  they  are  allowed  to  act  on  so 
great  a  number  of  nerves,  as  when  taken  into  the  mouth. 

391.  By  some  it  is  thought  that  all  the  nerves  of  taste 
are  not  of  the  same  quality;  that  is  to  say,  that  the  same 
things  produce  one  kind  of  sensation    through  the  nerves 
connecting  between  the  tip  of  the  tongue  and  the  mind,  and 
another  kind  of  sensation  through  the  nerves  connecting  be- 
tween the  sides  of  the  mouth  and  the  mind. 

They  illustrate  the  idea  by  what  every  one  may  notice,  viz.,  that 
some  articles  taste  differently  after  they  have  been  in  the  mouth  a  little 
time,  which  these  persons  suppose  to  be  owing  to  the  opportunity  they 
have  had  of  reaching  the  nerves  farther  back  in  the  mouth.  Others 
explain  this  phenomenon,  by  supposing  that  after  some  substances  have 
acted  for  a  little  while  upon  the  nerve  of  taste,  they  alter  the  nature  of 
the  nerve  in  such  a  manner  that  it  produces  new  kinds  of  sensations. 
One  thing  is  certain, 

392.  The  nature  of  the  nerves  of  taste  is  very  easily 
changed,  both  transiently  and  permanently. 

In  proof  of  this,  the  common  fact  need  only  be  mentioned,  that  food 


136  ORGANS  OF  SENSATION  OR  FEELING.          [CHAP.  II. 

which  it  is  very  disagreeable  for  us  to  taste  at  first,  becomes  delicious  in 
a  short  time,  not  more  because  we  become  accustomed  to  the  taste  than 
because  the  taste  is  changed.  The  taste  of  an  article  depends  much, 
also,  upon  what  articles  are  combined  with  it,  and  what  articles  have 
been  eaten  previously.  A  variety  of  articles  by  themselves,  produce 
such  sensations  we  cannot  relish  them  at  all ;  when  mixed  in  proper 
proportions  they  produce  exceedingly  agreeable  sensations.  In  this  lies 
the  great  secret  of  cooking,  viz.,  to  combine  articles  in  such  a  manner 
as  to  cause  them  to  relish.  Another  secret  consists  in  this,  viz.,  to 
place  articles  before  a  person  in  such  order,  that  eating  one  shall  increase 
the  relish  for  another,  and  improve  the  sensations  it  produces.  By 
breaking  both  these  rules,  some  housekeepers  with  the  greatest  abun- 
dance, never  have  any  thing  fit  to  eat,  or  one  thing,  if  good,  spoils  the 
taste  of  another  good  thing  which  follows  it ;  while  by  giving  attention 
to  these  principles  and  learning  how  the  taste  is  generally  acted  upon,  or 
particularly  acted  upon  in  particular  cases,  a  housekeeper  with  very 
small  means  will  always  have  a  delicious  table.  I  have  known  persons 
to  be  so  unskilful  as  to  put  on  the  table,  to  be  eaten  with  meats,  richly 
preserved  fruits,  perhaps  thinking  they  must  be  nice,  because  expensive, 
while  with  meats,  being  more  or  less  of  a  fatty  nature,  something  acid  is 
agreeable  ;  plain  apple  or  cranberry  sauce  would  have  improved  the 
meat,  and  the  meat  the  sauce ;  thus  the  old  proverb  is  true,  "  one  person 
will  prepare  a  better  dinner  with  a  shilling  than  another  with  a  pound." 
A  Frenchman  will  make  a  delicious  soup  with  what  ordinary  cooks  will 
throw  away.  In  this,  as  in  every  thing  else,  it  is  not  the  outlay  of 
money,  but  mental  application,  which  will  gain  the  desirable  end. 

393.  The  use  of  this  sense  is  to  give  pleasure  while  eat- 
ing, that  we  may  be  induced  to  chew  the  food  thoroughly, 
and  allow  it  to  be  mixed  with  a  good  supply  of  saliva ;  two 
very  important  things  in  the  digestive  process.  It  also  facil- 
itates digestion,  by  causing  a  free  flow  of  saliva.  "  The 
mouth  waters,"  is  a  frequent  description  of  the  effect  of  food 
before  it  is  tasted.  Much  more  powerful  in  the  same  way  is 
the  action  of  the  food  when  taken  into  the  mouth.  A  some- 
what similar  influence  causes  a  free  flow  of  digestive  fluids 
into  the  stomach,  as  shown  hereafter. 

As  previously  shown,  it  is  very  important  that  we  cultivate  a  relish 


SEC.  3.]  ORGANS  OF  SENSE.  137 

for  wholesome  food,  and  then  that  we  eat  it  only  when  it  is  highly 
relished,  and  that  we  enjoy  it  to  the  full,  by  the  allowance  of  proper 
time,  etc. 

394.  That  substances  may  produce  an  effect  on  the  nerves 
of  this  sense,  it  is  necessary  that  they  be  dissolved.     For 
this  purpose  the  constant  flow  of  the  saliva  is  well  adapted. 

395.  When  the  mouth  becomes  dry,  as  well  as  when  the 
organs  of  sensation  are  diseased,  the  sensation  of  taste  will 
be  wanting  or  very  much  changed. 

This  sense  in  animals  serves  them  instinctively  to  distinguish  between 
wholesome  and  unwholesome  food.  Some  have  thought  that  it  would 
be  the  same  with  man  in  the  uncultivated  state.  One  thing  is  certain, 
the  taste  of  animals,  as  well  as  of  man,  is  easily  changed,  and  as  the 
taste  of  animals  can  be  preserved,  so  can  that  of  man  without  change. 
If  a  child  be  always  fed  upon  milk,  it  will,  when  young,  desire  nothing 
else,  for  why  should  it  desire  to  taste  something  it  never  tasted  ?  If  we, 
when  mature,  find  any  new  thing,  we  have  so  little  desire  to  taste  it, 
that  we  use  great  caution,  and  at  first  taste  but  a  bit ;  indeed  we  have 
no  desire  to  taste  it.  The  child  who  has  never  had  a  bit  of  sugar  or 
sweetmeats  placed  in  its  mouth  will  never  desire  it,  and,  therefore,  never 
cry  or  fret  because  it  does  not  receive  it.  A  child  should  never,  there- 
fore, receive  the  least  thing  except  its  wholesome  food,  until  it  is  old 
enough  to  understand  why  it  should  have  but  little  of  certain  things, 
and  only  at  certain  times.  Thus  will  the  mother  save  the  disposition 
of  the  child  from  a  great  source  of  injury,  and  save  herself  much  trouble, 
while  certainly,  the  health  of  the  child  will  be  much  the  better.  I  have 
known,  as  every  one  has,  a  mother  to  give  a  child  a  bit  of  sweetmeats 
which  has  been  the  means  of  a  hundred  crying  fits  ;  for  every  time  the 
child  saw  the  like,  it  would  wish  to  eat,  and  the  mother  would  not  dare 
to  give  what  the  child  wished. 

D.    The  Sense  of  Smell. 

396.  To  understand  this  sense  we  must,  in  the  first  place,  give  atten- 
tion to  the  objects  which  act  upon  its  organs.  The  rose  may  be  at  a 
distance  from  us,  and  yet  we  perceive  its  odor.  The  whole  air  is  some- 
times filled  with  the  fragrance  of  the  fresh-blown  clover  field.  The  rose 
itself  does  not,  of  course,  affect  us.  The  usual  opinion  is,  that  exceed- 
ingly minute  particles  of  the  rose  and  all  odorous  bodies,  are  continually 


138  ORGANS  OF  SENSATION  OR  FEELING.  [cHAP.  II. 

coming  off  from  them,  and  that  these  act  upon  the  nerves.  Of  course,  if 
this  theory  be  correct,  the  greater  the  number  of  particles  acting  on  the 
nerves  at  the  same  time,  the  more  powerful  would  be  the  sensation ;  and 
it  is  usually  found  that  the  most  odorous  articles  are  very  volatile  (fly- 
ing). But  some  articles  have  been  said  to  render  a  large  space  fragrant 
with  their  qualities  for  years  ;  and  yet  without  losing  weight  appreciably. 
We  can  hardly  conceive  of  particles  so  minute  as  this  would  require — 
and  a  variety  of  arguments  have  induced  me  to  suppose  the  ordinary 
philosophy  was  not  quite  correct ;  but  it  explains  most  phenomena  well 
enough,  and  I  shall  adopt  it.  Suppose  the  air  then  to  contain  particles 
of  a  rose  or  any  thing  else,  it  will  next  be  necessary  to  have  the  air  pass 
over  the  nerves  ;  and  the  greater  the  number  of  nerves  it  passes  over,  the 
greater  the  probability  that  many  of  the  nerves  will  be  affected  by  the 
particles,  few  or  many,  which  the  air  contains — and  the  greater  the 
quantity  of  air  passing  over  the  nerves,  the  greater  the  probability  that 
many  nerves  will  be  acted  upon,  and  an  intense  effect  be  produced 
therefrom. 

397.  The  nose  is  exceedingly  well   adapted  to  be  the 
organ  of  the  sense  of  smell. 

The  lining  of  the  nose  is  also  the  organ  of  the  sense  of  touch  and 
common  feeling ;  as  substances  may  produce  the  sensation  of  touch  or 
pain,  without  causing  that  of  smell.  By  disease,  also,  a  person  may  be 
devoid  of  either  the  sense  of  smell  or  touch,  without  the  other  being  lost. 
There  must,  therefore,  be  two  kinds  of  nerves  connecting  between  the 
nose  and  mind — which  is  found  to  be  the  case. 

398.  It  is  composed  above  of  a  bony  framework,  which 
is  lengthened  down  by  cartilage. 

The  yielding  nature  of  this,  prevents  the  prominence  of  the  nose 
from  being  objectionable  on  account  of  its  liability  to  accident ;  while  the 
elasticity  of  the  cartilage,  preserves  a  free  passage  to  the  air.  The 
yielding  nature  of  the  cartilaginous  portion  also  allows  the  passage  to  be 
closed,  if  the  air.be  unpleasant,  or  narrowed  when  it  is  desirable  to  in- 
hale the  air  with  increased  force. 

399.  The  nose  is  divided  above  by  bone,  which  is  also 
lengthened  down  by  cartilage. 

This  increases  the  extent  of  surface  in  either  half  of  the  nose,  and  in 
fact  divides,  for  all  the  purposes  of  smell,  the  nose  into  two  noses ;  for 


SEC.  3.]  ORGANS  OF  SENSE.  139 

the  sense  of  smell  may  be  lost  in  respect  to  one  nostril,  and  may  remain 
in  respect  to  the  other.  And  the  nature  of  the  nerves  connecting  be- 
tween the  nostrils  are  sometimes  different ;  so  that,  as  some  persons  have 
one  sensation  when  a  substance  acts  on  one  side  of  the  tongue,  and  a 
different  sensation  when  the  same  substance  is  moved  on  the  other  side 
of  the  tongue — so  some  persons  have  one  sensation  produced  when  odor 
acts  through  one  side  of  the  nose,  and  another  sensation  when  the  same 
particles  act  through  the  other  side. 

400.  Several  bones,  called  turbinated  (coiled)  or  spiral 
(Fig.  52),  are  attached  by  one  edge  to  the  outer  and  upper 
side  of  the  inside  of  the  nose.  The  other  edge  hangs  down 
into  the  nasal  passage,  and  is  somewhat  coiled ;  though  not 
as  much  in  men  as  in  many  animals.  • 

Fig.  52. 


Fig.  52.— Is  a  perpendicular  section  of  the  face-bones,  through  the  nose  and  across 
its  passages.  The  figures  7,  7,  are  placed  in  the  sockets  of  the  eyes  ;  12,  is  the  cheek- 
bone, within  which  is  seen  the  antrum  with  a  small  bit  of  its  lining  raised  up.  In  the 
antrum  of  the  other  side,  a  bristle  is  represented,  thrust  up  through  an  opening  into 
the  nose,  the  cavities  of  which  are  divided  by  the  vomer  11,  and  partially  divided  by 
the  lower  spongy  bones  10, 10,  and  middle  spongy,  to  which  the  lines  from  7  lead ;  18, 
the  roof  of  the  mouth. 

By  this  arrangement,  two  objects  are  gained.  In  the  first  place,  the 
lining  of  the  nostrils  presents  much  more  surface  to  the  action  of  the  air, 
and  in  the  next  place,  the  nasal  passage  being  narrowed,  there  is  much 
more  probability  that  the  odorous  particles,  which  the  passing  air  contains, 
will  act  upon  one  part  or  another. 

401.  The  nerves  of  smell   commence  in  papillae,  found 
beneath  the  surface  of  the  delicate  lining  of  the  nasal  passages. 


140  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

Thus,  as  the  air,  by  the  action  of  the  breathing  apparatus,  is  swept 
through  the  passages  of  the  nose,  the  odorous  particles  of  one  substance 
produce  one  effect,  those  of  another  substance  produce  another  effect. 
The  question  might  be  asked,  if  a  particle  of  substance,  after  it  had  acted 
on  one  nerve,  could  be  carried  on  to  act  on  another  1  This  is  not  known, 
probably  it  could  not. 

402.  To  facilitate  the  action  of  odorous  particles,  it  is  ne- 
cessary that  the  lining  of  the  nose  should  be  kept  in  a  proper 
condition  by  a  substance,  serving  the  same  purpose  as  the 
oily  substance  poured  out  constantly  on  the  skin. 

It  is  formed  in  a  similar  manner,  and  differs  in  its  nature,  only  to 
be  better  adapted  to  the  wants  of  the  part  to  which  it  is  supplied.  It 
is  very  similar  to  the  substance  which  is  supplied  to  the  lining  of  the 
mouth,  and  readily  seen,  looking  like  the  white  of  egg,  if  a  spoon  or 
knife  be  scraped  gently  down  upon  the  surface  of  the  tongue. 

403.  The  lining  of  the  nose  is  also  kept  in  a  proper  con- 
dition by  the  fluid  which  has  already  served  a  similar  pur- 
pose in  the  eyes. 

When  therefore  either  of  these  fluids  is  wanting,  the  power  of  the 
sense  of  smell  is  correspondingly  deficient.  So  on  the  other  hand,  when 
the  supply  is  too  abundant  the  sense  of  smell  is  injured.  Both  of  these 
things  are  frequently  illustrated  by  the  effect  of  colds. 

404.  In  man,  this  sense  seems  to  be  chiefly  useful  by  in- 
creasing the  pleasures  of  existence.    It  prepares  and  increases 
the  appetite  for  the  preparing  food. 

This  sense  is  so  seldom  wanting  at  birth,  (I  never  knew  but  one 
case,)  that  it  may  be  of  much  more  use  than  at  first  appears.  In  case 
of  animals,  it  appears  of  great  use  in  distinguishing  their  food,  and  won- 
derful things  are  told  by  travellers  and  naturalists  of  the  acuteness  of 
smell  of  certaid  birds,  etc.  But  I  do  not  place  confidence  in  them,  as 
there  is  no  reason  it  should  be  so.  The  acuteness  of  smell  in  case  of  the 
hound  is  owing,  in  great  part,  to  the  great  extent  of  lining  surface  of  his 
nostrils,  by  which  a  large  number  of  nerves  can  be  presented  to  the 
action  of  air  which  he  snuffs. 

405.  The  sense  of  smell  seems  to  affect  the  sense  of  taste, 
or  rather  certain  sensations  which  we  call  sensations  of  taste, 


SEC.  3.]  ORGANS  OF  SENSE.  141 

seem  to  be  made  up  of  effects  produced  through  the  organs  of 
smell  and  through  the  organs  of  taste. 

For  if  the  nostrils  be  closed,  certain  articles  produce  little  if  any  taste. 
An  idea  to  be  taken  advantage  of,  when  a  person  must  swallow  un- 
pleasant things.  The  near  alliance  of  the  nerves  of  taste  and  smell  is 
also  seen  by  what  everyone  has  noticed,  that  one  thing  tasies  as  another 
one  smells,  or  vice  versa.  That  is,  the  sensation  which  one  thing  pro- 
duces through  the  nerves  of  taste,  is  similar  to  the  effect  another  thing 
produces  through  the  nerves  of  smell. 

406.  There  are  various  cavities  connected  by  small  open- 
ings or  tubes  with  the  nostrils.      1st.  There  is  one  within  each 
cheek  bone,  called  an  antrum,  with  a  tube  opening  into  the  side 
of  the  nostril.  There  is  one  within  the  ridge  of  bone  felt  beneath 
each  eyebrow,  called  a  frontal  sinus,  with  a  tube  opening  into 
the  upper  part  of  the  nose.     The  inner  end  of  this  sinus 
sometimes  almost  meets  that  of  the  opposite,  its  other  end 
being  found  within  the  outer  end  of  the  eyebrow.    Sometimes 
they  are  a  little  distance  from  each  other  at  their  inner  ex- 
tremities, and  short  or  long  as  the  case  may  be.     Sometimes 
they  are  broad,  either  up  and  down  or   from  forward  back, 
being  large  or  small  as  the  case  may  be.     Sometimes  their 
size  is  indicated   by  an  external  prominence,  sometimes  not. 
There  are  other  small  cells  or  cavities  in  the  bones  forming 
the  roof  of  the  nose  ;  their  tubes  open  into  the  top  of  the  nose. 

407.  The  skin  or  membrane  lining  these  cavities  is  con- 
tinuous with  that  Iming  the  no§e.      It  forms  and  pours  upon 
its  surface  a  similar  substance,  though  not  in  so  large  quan- 
tity.     The  tubes  heretofore  mentioned  are  the  outlet  of  this 
fluid.      Colds   sometimes  increase,  sometimes  diminish   the 
quantity  of  fluid  formed,  and  sometimes  at  the  same  time 
cause  a  closure  of  the  outlet.     A  collection  then  takes  place 
in  the  cavity.     Severe  consequences  usually  follow  in  a  short 
time.     Similar  disease  of  the  membrane,  though  not  the  re- 
suit  of  colds,  will  produce  like  results. 


142  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

E.  Sense  of  Sight. 

408.  The  eye  is  very  admirable,  both  on  account  of  its  beautiful 
structure,  and  the  perfect  manner  in  which  it  fulfils  its  duties.     But  it  is 
exceedingly  difficult  to  render  its  mode  of  action  perfectly  clear.     With 
the  aid  of  lithographs,  however,  if  the  reader  will  assist  with  his  imagi- 
nation, and  give  his  undivided  attention,  the  task  may  perhaps  be  ac- 
complished.     He  must,  however,  pardon  the  author,  if,  in  the  earnest 
attempt  to  render  the  subject  clear  to  every  understanding,  the  descrip- 
tion should  appear,  by  the  homeliness  or  simplicity  of  expression  or  illus- 
tration, to  fall  below  the  dignity  of  a  book  treating  upon  op.ics.      If  he 
be  in  the  habit  of  reading  upon  these  subjects,  he  will  confer  a  favor  on 
the  author,  and   perhaps  on  himself,  by  reading  as  if  a  beginner,  follow- 
ing step  by  step,  without  anticipation,  as  explanations  may  then  appear 
proper,  which  otherwise  would   seem  unnecessary ;    and  the  language 
used  is  intentionally  different  from  what  is  usual ;    some  very  familiar 
expressions  will  carefully  be  avoided,  nor  should  the  reader  allow  his 
mind  to  suggest  them.      The  eye  is  neither  a  telescope  nor  a  micro- 
scope, but  an  apparatus  with  which  to  see.      How  do  we  see  1    is  the 
question  to  be  answered.     And  if,  in  following  the  author,  the  reader  ar- 
rive at  the  same  conclusions  he  has  often  before,  as  it  is  expected  he  will, 
it  will  perhaps  be  by  a  way  somewhat  new,  except  to  physiologists,  and 
free  from  many  sources  of  confusion  to  which  descriptions  of  this  sense 
are  usually  liable. 

409.  If  the  eye  be  directed  toward  yonder  tree,  it  apparently  produces 
a  sensation ;    that  is,  it  is  seen.      If  the  eye  be  closed,  the  sensation 
ceases. 

410.  The  eye  is,  therefore,  the  organ  of  sense  through 
which  the  sensation  is  produced.  It  is  the  organ  of  the  sense 
of  sight. 

It  will  by  this  time  be  easily  remembered,  that  when  an  effect  is  pro- 
duced on  the  nerve  commencing  in  the  organ  of  sense,  that  effect  ia 
called  an  impression.  This  effect  or  impression  acts  through  the  nerve 
and  brain  upon  the  mind,  causing  a  sensation.  It  will  be  convenient  in 
this  division  of  the  section,  to  make  free  use  of  the  word  impression. 

411.  If  the  tree  be  removed,  the  sensation  will  cease. 

412.  The  tree  must  therefore  be  one  of  the  causes  of  the 
impression  made  upon  the  eye. 


SEC.  3.]  ORGANS  OF  SENSE.  143 

413.  But  the  tree  is  at  such  a  distance  that  it  cannot  itself  act  on  the 
eye.  Yet  something  must  act  on  the  eye,  and  something  must  be  caused 
to  act  on  the  eye  by  the  tree.  That  something  is  called  light. 

414.  Light,  therefore,  is  that  something  which  objects 
more  or  less  distant  cause  to  act  on  the  eye  and  produce 
impressions. 

Some  think  that  light  is  composed  of  very  small  particles,  which  ob- 
jects cause  to  act  on  the  eye.  Others  think  that  there  is  a  substance  very 
much  more  subtle  than  air,  existing  throughout  the  universe.  This  fluid, 
as  it  is  sometimes  called,  or  ether,  as  it  is  also  called,  is  supposed 
to  be  thrown  into  waves  by  the  action  of  objects,  and  these  waves  caused 
to  act  on  the  eye.  It  will  make  no  difference  at  present,  in  any  practi- 
cal respect,  which  theory  is  adopted  ;  but  as  the  language  used  in  con- 
nection with  the  first  mentioned  is  more  easily  understood,  light  will  be 
here  considered  as  composed  of  exceedingly  minute  particles.  These 
always  move  in  straight  lines  till  they  meet  some  object  which  turns 
their  course,  when  they  again  move  in  straight  lines.  A  series  of  these 
particles  of  light  following  each  other,  is  called  a  ray  or  beam  of  light. 
Whether  in  a  ray  of  light  the  particles  are  very  near  each  other,  or  at 
considerable  distance,  is  not  known  ;  nor  is  it  known  whether  they  are 
nearer  in  some  cases  than  in  others.  The  quickness  or  velocity  with 
which  they  move  is  almost  incredible. 

415.  But  in  a  few  hours  the  sun  will  set,  and  leave  the  world  in 
darkness.      The  tree  will  remain,  and  the  eye  may  remain,  but  the  tree 
will  not  produce  any  sensation.      The  action  of  the  tree,  therefore,  de- 
pends upon  the  sun.      But  the  sun  does  not  touch  the  tree.      The  sun 
must,   therefore,  cause  something  to   act  upon   the   tree,   causing  the 
tree  to  cause  the  light  to  act  upon  the  eye. 

416.  How  this  is,  is  made  known  by  examining  the  nature  of  light. 
The  particles  of  light,  when  striking  against  certain  objects,  bound  off 
like  india-rubber  balls.     If  a  handful  of  these  be  thrown  against  the  wall, 
some  would  bound  off  or  be  reflected  (turned  back)  in  an  upward  direc- 
tion, some  downward,  some  to  one  side,  others  to  the  other  side,  and 
thus  be  scattered  over  the  entire  room.     Thus  is  it  with  light. 

417.  The  idea,  therefore,  is  this,  viz.,  that  the  sun  acts  upon  the 
tree  by  means  of  light,  the  particles  of  which  pass  from  the  sun  to  the 
tree  upon  which  they  strike  ;  it  then  reflects  or  bends  them  in  various 
directions,  and  some  of  the  particles  being  bent  or  reflected  so  as  to 


144  ORGANS  OF  SENSATION  OR  PEELING.  [CHAP.  II. 

come  in  a  straight  line  to  the  eye  of  the  observer,  an  effect  or  impression 
is  produced.     Hence 

418.  Various  objects  produce  an  effect  through  the  eye 
by  reflecting  light  upon,  or  rather  into  it. 

419.  But  yonder  house  by  the  side  of  the  tree  also  produces  an  effect 
or  impression  upon  the  eye.  The  light  of  the  sun  must  also  strike  upon 
that  and  be  reflected  to  the  eye.  But  the  sensation  produced  is  different 
from  that  produced  by  the  light  coming  from  the  tree.  The  impression 
must  of  course  be  different,  and  the  light  producing  the  impression  must 
be  different,  therefore  the  light  coming  from  the  tree  must  be  different 
from  that  coming  from  the  house.  But  the  light  coming  from  the  sun  to 
the  tree  is  precisely  similar  to  that  coming  from  the  sun  to  the  house. 
These  objects  must,  therefore,  do  something  more  than  merely  bend  the 
light;  they  must  change  it  so  that  it  will  cause  different  impressions 
after  it  has  left  them,  for  the  light  is  similar  before  it  comes  to  them,  but 
different  afterwards.  How  this  is  will  be  understood  by  noticing,  in  the 
first  place,  that 

420.  The  light  coming  from  the  sun  is  composed  of  three 
kinds  of  light. 

421.  When  all  three  kinds  act  on  a  single  nerve  at  the  same  time, 
they  produce  the  same  sensation  as  when  light  from  the  sun  acts  on  it.  It 
is  called  the  sensation  of  white  light,  or  whiteness.  If  one  kind  act  by 
itself,  it  produces  the  sensation  of  red.  If  a  second  kind  act  by  itself,  it 
produces  the  sensation  of  yellow.  If  the  third  kind  act  by  itself,  it  pro- 
duces the  sensation  of  blue.  If  the  first  and  second  kinds,  in  proper 
proportions,  act  at  the  same  time  upon  the  same  nerve,  they  produce  a 
sensation  of  orange.  If  the  first  and  third  kinds  in  proper  proportions 
act,  they  produce  a  sensation  of  purple.  If  the  second  and  third  kinds 
in  proper  proportions  act  on  the  same  nerve,  they  produce  the  sensation 
of  green.  Thus  every  variety  of  sensation  of  color  is  caused  by  the 
action  of  one  or  several  kinds  of  light  at  the  same  instant  on  the  same 
nerve.  When  the  nerves  are  not  acted  on  by  light  of  any  kind,  they 
cause  a  sensation  of  blackness,  as  when  a  person  goes  into  a  perfectly 
dark  room.  Sensations  produced  by  the  action  of  any  kind  of  light 
singly,  are  called  simple  sensations.  Sensations  produced  by  the 
action  of  more  than  one  kind  of  light,  are  called  compound  sensations. 
If  it  be  asked,  How  are  all  these  things  known  ?  The  answer  is,  by  the 
use  of  proper  apparatus  the  light  of  the  sun  can  be  separated  into  three 


SEC.  3.]  ORGANS  OF  SENSE.  145 

kinds,  either  of  which,  or  any  combination  of  them,  can  be  made  to  act 
on  a  nerve  of  the  eye  at  the  same  instant.  We  are  now  prepared  to  notice, 
in  the  second  place,  that 

422.  Some  objects  absorb  (drink  up)  all  the  light  that 
falls  upon  them,  while  others  reflect  all  that  falls  upon  them ; 
while  other  objects  again,  absorb  one  kind,  or  two  kinds,  or 
part  of  one  kind,  or  two  kinds,  as  the  case  may  be,  and  reflect 
the  rest. 

423.  The  reason  is  now  instantly  seen  why  objects  produce  different 
impressions.     Yonder  house  absorbs  the  yellow  and  blue  light  and  re- 
flects the  red,  and  hence  produces  a  sensation  of  red.     The  tin  upon  the 
roof  does  not  absorb  any,  but  reflects  all  kinds  just  as  they  come  from 
the  sun,  and  the  same  effect  is,  of  course,  produced  as  if  the  light  came 
from  the  sun  directly  to  the  eye ;  a  sensation  of  dazzling  whiteness. 
The  posts  in  the  yard  absorb  all  the  light  and  do  not  reflect  any,  nor 
produce  any  effect  on  the  eye,  and  the  want  of  this  effect  causes  the 
sensation  of  black,  and  we  say  we  see  the  posts  to  be  black.     The 
leaves  of  the  tree  absorb  the  red  light  and  reflect  the  yellow  and  blue, 
which  together,  acting  upon  the  eye,  cause  the  sensation  of  green.     But 
when  the  frosts  of  autumn  shall  change  the  nature  of  the  leaves,  some 
of  them  will  absorb  the  red  and  the  blue,  reflecting  only  the  yellow, 
and   producing,  therefore,  the   sensation  of  yellow,  while  others  will 
absorb  the  blue  and  yellow,  and  reflect  only  the  red.     Thus  by  the 
change  in  the  nature  of  the  leaves,  and  their  power  of  absorption  and 
reflection  of  light,  which  falls  upon  them,  is  produced  all  the  gaudy 
beauty  of  our  autumnal  forests.     For  when  night  comes  on  and  there  ia 
no  light  to  be  reflected,  all  things  alike  want  the  power  of  producing 
sensations,  and  as  the  eye  strives  to  pierce  the  darkness  of  the  forest,  it 
causes  only  the  sensation  of  blackness. 

424.  Some  objects  produce  light,  which  passing  directly 
to  the  eye,  causes  sensations.  Thus  objects  are  of  two  kinds. 
1st.  Those  which  produce  sensations  by  their  own  light,  and 
2d.  Those  which  produce  sensations  by  reflecting  light  pro- 
duced by  other  objects. 

The  sun,  candle,  the  fire,  and  the  like,  are  examples  of  objects  causing 
sensations  by  their  own  light.  The  kind  of  sensation  they  will  produce, 
will  depend  on  the  kind  of  light  they  produce.  The  sun,  "  the  great 

7 


116  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

fountain  of  light,"  produces  all  three  kinds  of  light  at  the  same  time. 
Some  other  light-giving  objects,  however,  produce  but  one  kind  of  light ; 
most  objects,  however,  produce  several  kinds.  It  is  now  desirable  to 
state  distinctly  an  important  proposition. 

425.  When  different  kinds  of  light  act  at  the  same  time 
on  the  end  of  the  same  nerve,  a  compound  sensation  must  be 
produced.     In  order,  therefore,  to  have  the  light  coming  from 
different  objects  produce  distinct  sensations,  it  must  act  on  the 
commencing  points  of  different  nerves,  and  the  more  perfectly 
this  is  accomplished  the  more  distinct  will  be  the  resulting 
sensations  \  this  is  the  great  office  of  the  eye. 

Yonder  now  is  the  house,  which  produces  the  sensation  of  red,  and 
the  leaves  of  the  tree,  which  produce  the  sensation  of  green,  because  the 
red  light  is  reflected  by  the  house,  and  the  yellow  and  blue  by  the  leaves. 
If  the  light  from  these  two  objects  acted  on  the  end  of  the  same  nerve, 
at  the  same  time,  the  sensation  would  be  that  of  white,  because  all  three 
kinds  of  light  would  be  acting  at  the  same  time  on  the  same  nerve. 
But  the  red  light  from  the  house  does  enter  the  eye  at  the  same  time 
with  the  yellow  and  blue  light  coming  from  the  leaf,  and  yet  a  distinct 
effect  is  produced.  Therefore  there  must  be  more  than  one  nerve  in 
the  eye,  and  the  eye  must  be  so  made  as  to  cause  the  light  coming  from 
the  house  and  entering  it,  to  act  on  one  nerve,  and  the  light  entering  it 
from  the  leaf  to  act  on  another  nerve.  It  must  be  the  same  in  respect 
to  the  light  coming  from  any  and  every  object  we  see  ;  thus, 

426.  The  number  of  objects  which  we  can  distinguish 
being  very  great,  the  number  of  nerves  commencing  in  the 
eye  must  correspond  (Fig.  53). 

That  the  reader  may  comprehend  how  the  different  nerves  are  acted 
upon  by  the  light  coming  from  different  objects,  at  the  same  time,  and 
in  such  manner  that  each  nerve  acted  on  shall  be  affected  only  by  the 
light  coming  from  its  own  object ;  let  him  try  the  experiment  of  placing 
several  candles  near  each  other.  Then  having  made  a  pin-hole  in  a  sheet 
of  paper  or  pasteboard,  hold  it  in  such  a  manner  within  a  few  inches 
of  the  candles,  that  the  light  from  all  of  them  will  shine  through  the 
pin-hole  ;  let  then  some  object  be  held  a  little  distance  from  the  pin-hole, 
upon  the  side  of  the  paper  opposite  the  candles.  He  will  thus  see  that 
light  moves  in  straight  lines,  for  the  light  goes  directly  on  from  the  pin- 


SEC.  3.]  ORGANS  OF  SENSE.  147 

Fig.  53. 


Fig.53. — 3,  Represents  the  outer  coats  of  the  back  part  of  the  eye.  1,  The  optic  nerve 
composed  of  millions  of  fibres.  2.  An  ideal  respresentation  of  the  commencement  of 
the  fibres.  Between  the  nerves  and  outer  coats  13  seen  the  pigmentum  nigrum. 

hole  in  the  same  direction  it  had  while  coming  from  the  candle  to  the 
pin-hole,  and  he  will  quickly  see  which  spot  the  light  from  any  candle 
produces,  by  blowing  out  a  candle,  for  its  spot  will  instantly  vanish, 
and  reappear  if  the  candle  be  lighted.  He  will  also  see  that  the  light 
from  one  candle  crosses  that  from  another  at  the  pin-hole,  without  any 
interference.  How  or  why  this  is,  cannot  be  told,  but  it  is  an  evident 
fact. 

If  now  he  look  at  lithograph  Plate  5,  Fig.  1,  he  will  notice  a  repre- 
sentation of  the  eye  in  outline,  as  a  box  of  a  spherical  form,  with  an  open- 
ing in  front ;  just  back  of  this  is  a  partition  with  a  hole  in  it  correspond- 
ing to  the  pin-hole  in  the  pasteboard,  and  in  the  back  part  is  seen  the 
commencing  extremities  of  a  great  number  of  nerves,  each  one  of  which 
extends  back  to  the  brain.  In  front  of  the  eye  are  placed  three  candles, 
producing  red,  yellow,  and  blue  light.  When  the  light  coming  from 
each  is  mingled,  as  it  is  in  passing  through  the  hole  in  the  partition,  a,  it 
would  cause  the  sensation  of  white  light,  if  a  nerve  were  there  to  be 
acted  on  ;  but  when  the  red  light  has  gone  through  the  hole,  it,  like  the 
others,  pursues  its  straight  course,  and  therefore  acts  on  its  own  nerves  at 
the  same  time  the  blue  and  yellow  light  act  on  their  nerves. 

427.  The  more  light  there  is  acting  on  any  nerve  at  the 
same  time,  the  more  intense  will  be  the  sensation  produced. 

This  is  almost  self-evident.  When  we  go  into  a  nearly  dark  room, 
there  is  so  little  light  acting  on  the  nerves,  that  objects  can  hardly  be 
discerned  ;  while  if  we  go  out  doora,  of  a  bright  winter's  day,  the  light 


148  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

reflected  from  the  snow,  painfully  dazzles.  Under  some  circumstances, 
therefore,  it  will  be  desirable  to  have  as  much  light  as  possible  enter  the 
eye ;  while  in  other  cases,  it  would  be  desirable  to  shut  out  the  light. 
It  is  evident  such  an  end  could  be  gained  by  enlarging  or  lessening  the 
hole  in  the  partition  a.  For  if  it  should  be  enlarged,  more  light  would 
be  admitted ;  while  if  it  were  lessened,  so  much  light  as  now  could  not 
reach  the  nerve. 

428.  If  the  reader  take  the  pains  to  hold  a  candle  near  to  the  eye, 
and  remove  it  and  re-bring  it  towards  the  eye  of  another  person,  he  will 
perceive  an  enlargement  and  lessening  of  the  hole,  called  the  pupil,  seen 
in  the  colored  part  of  the  eye,  called  the  iris,  which  corresponds  to  the 
partition  (Lith.  PI.  5,  Fig.  1)  a. 

It  would  now  seem  that  all  the  requirements  for  seeing  are  obtained; 
but  the  most  difficult  part  of  the  matter  yet  remains.  It  is  seen  that  the 
light  from  three  candles  (Lith.  PI.  5,  Fig.  1)  acts  upon  a  large  portion  of  the 
nerves  in  the  eye.  But  with  the  eye  we  can  distinguish  a  thousand 
candles,  which  could  not  of  course  be,  if  no  other  arrangement  existed 
than  that  already  described.  If  the  hole  in  the  partition  a  be  made 
very  small,  then  only  a  little  light  from  each  object  would  pass  through, 
and  act  on  a  correspondingly  small  space,  in  the  eye  ;  and  there  would 
then  be  room  for  the  action  of  light  from  a  great  many  different  objects. 
It  has,  however,  been  seen,  that  in  a  dimly  lighted  room,  where  only  a 
very  small  amount  of  light  acted  on  the  nerves,  but  a  slight  effect  was 
produced.  With  so  small  an  amount  of  light  as  would  pass  through  a 
pin-hole,  acting  on  the  nerve,  the  effect  would  not  be  so  powerful  as 
necessary ;  more  light  must,  therefore,  be  allowed.  But  when  the  open- 
ing is  large,  it  is  seen  in  Lith.  PI.  5,  Fig.  1,  that  the  light  acts  over 
many  nerves ;  so  that  no  more  light  acts  on  one  nerve,  than  if  the  hole 
in  partition  a  were  smaller.  Though  in  this  case  the  sensation  would  be 
stronger,  it  would  yet  be  feeble.  If,  however,  any  thing  can  be  done  by 
which  the  light  passing  through  the  hole  in  the  partition,  which  I  will  now 
call  the  pupil,  can  be  concentrated  (brought  to  a  centre  or  point) — that  is 
to  say,  the  red  light  be  brought  to  a  point  by  itself,  and  the  blue  and  yellow 
light  brought  to  points  each  by  itself— the  desired  end  will  be  gained  ; 
for  then  all  the  light  from  one  object  passing  through  the  pupil  will  be 
made  to  act  on  a  single  nerve — and  there  can  be  as  many  different  sensa- 
tions as  there  are  nerves,  if  there  are  only  as  many  objects  to  cast  their, 
light  through  the  pupil.  To  understand  how  this  is  accomplished, 
we  must  notice  a  third  effect,  which  is  produced  upon  light  by  some 
objects. 


SEC.  3.]  ORGANS  OF  SENSE.  149 

429.  Some  objects  transmit  (send  through)  the  light  fall 
ing  upon  them — as  window-glass  transmits  the  light  of  tht 
sun.     Such  objects  are  called  transparent. 

Some  objects  transmit  one  kind,  and  reflect  the  rest ;  or  transmit  a 
part  of  all,  and  reflect  a  part  of  all.  There  are  very  few,  if  any  objects, 
which  transmit  all  the  light  falling  upon  them. 

430.  If  a  ray  of  light  fall  perpendicularly  upon  the  sur- 
face of  a 'transparent  object,  as  C,  D  (Fig.  54)  falling  on 
the  surface  S,  I,  the  light  will  not  be  bent  out  of  its  course. 


Fig.  54.— R,  S,  T,  U,  represents  a  ray  of  light  passing  obliquely  from  the  air  S,  I, 
into  the  glass  A,  B— and  from  that  into  the  air  P,  T ;  R,  O,  would  be  the  direct  line 
S,  P ;  I,  T,  perpendiculars ;  C,  D,  a  ray  of  light  entering  the  glass  perpendicularly,  and 
of  course  not  bent. 

431.  If  a  ray  of  light  fall  upon  the  surface  of  a  transpa- 
rent object  in  an  oblique  or  slanting  manner,  the  light  will 
be  bent  just  at  the  surface  of  the  object  it  is  entering,  as 
shown  by  R,  S,  T,  U,  Fig.  54. 

An  experiment  illustrating  this  can  be  tried  by  putting  a  quarter  of 
a  dollar  in  an  empty  bowl.  Then  place  the  bowl  in  such  a  position  that 
the  light  coming  from  the  money  over  the  edge  of  the  bowl  will  not 
enter  the  eye,  but  pass  a  little  above  it  as  in  (Fig.  55)  the  line  of  light 
a,  b.  If  water  be  poured  into  the  bowl,  the  light  which  passes  from  the 
money  perpendicularly  into  the  air  at  c,  a,  will  not  be  bent,  but  pass  the 
same  as  before  the  water  is  poured  into  the  bowl ;  but  all  the  light  pass- 
ing from  the  money  through  the  water  and  entering  the  air  in  a  slanting 
direction,  will  be  bent,  and  the  light  which  passes  in  the  line  from  the 


150  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II, 

money  to  the  edge  of  the  bowl,  when  there  was  no  water  in  the  bowl, 
passes  in  the  same  line  as  far  as  the  surface  of  the  water,  but  as  soon  as 
it  enters  the  air  it  is  bent  and  strikes  against  the  bowl,  while  the  light 
which  left  the  money  in  the  line  a,  b,  before  the  water  was  poured  into 
the  bowl,  follows  the  same  course  as  far  as  the  surface  of  the  water, 
when  it  is  bent  so  as  to  take  the  line  a,  d,  e,  which  passes  into  the  eye 
and  produces  an  impression.  This  is  the  reason  why  pouring  water  into 
the  bowl  enables  a  person  to  see  the  money,  though  the  bowl  and  eye 
are  not  moved. 

Fig.  55. 


432.  The  more  slanting  or  obliquely  the  light  enters  from 
one  object  into  another,  the  more  is  it  bent. 

This  is  represented  by  the  lines  in  Fig.  55,  between  a,  b,  and  a,  f. 

433.  It  is  also  seen  that  the  light  passing  from  the  water  into  the 
air,  in  Fig.  55,  bends  from  the  perpendicular  c,  a,  to  the  surface  of  the 
air.  This  is  true  of  the  light  passing  out  of  the  water  on  each  side 
of  the  perpendicular.  Now  the  air  into  which  the  light  passes,  is  not 
as  dense  as  the  water  out  of  which  the  light  passes  into  the  air.  There- 
fore as  this  is  always  the  case, 

434.  It  is  a  rule  or  principle  that  light  passing  from  a 
denser  or  more  solid  object  into  a  less  dense  or  less  solid  ob- 
ject, is  bent  from  the  perpendicular  to  the  surface  it  is  enter- 
ing. 

435.  In  Fig.  56,  light  is  represented  as  passing  from  air  into  water, 
thence  into  glass,  thence  into  air  again.  In  passing  from  air  into 
the  water,  the  light  is  seen  to  be  bent,  but  is  now  bent  towards  the 


SEC.  3.]  ORGANS  OF  SENSE.  151 

perpendicular  to  the  surface  which  it  is  entering,  because  the  object,  viz. 
the  water  which  it  enters,  is  more  dense  than  the  air  which  it  leaves.  As 
it  enters  th"  irin.-s.  it  is  observed  to  bend  again.  This  time  it  also  bends 
towards  the  p-.^pendicular  to  the  surface  it  is  entering,  because  the  glass 
is  more  tU  n. -e  than  water.  But  after  passing  through  the  glass  it  passes 
into  the  less  dense  air,  when  it  bends  from  the  perpendicular,  and  bends 
much  more  than  at  either  of  the  previous  times,  because  the  re' is  much 
more  difference  between  the  density  of  the  glass  and  air,  than  between 
the  air  and  water  or  water  and  glass. 

Fig.  56. 


Fig.  56.— A,  D,  is  a  ray  of  light  passing  from  air  into  the  more  dense  water  at  D, 
where  it  is  bent  towards  the  perpendicular  C,  D.  E,  H,is  the  continuation  of  the  same 
ray  through  the  denser  glass  which  causes  the  light  to  bend  at  E  towards  the  perpen- 
dicular E,  F.  H,  R,  is  the  continuation  of  the  same  ray  through  the  less  dense  air 
which  causes  the  light  to  bend  from  the  perpendicular  H,  G,  and  to  a  great  degree  be- 
cause of  the  great  difference  in  the  densities  of  air  and  glass. 

436.  It  is  a  rule  of  universal  application  that  light   in 
passing  from  a  less  dense  into  a  denser  object,  is  bent  towards 
the  perpendicular  to  the  surface  it  is  entering. 

437.  It  is  also  a  rule  that  the  more  the  density  of  bodies 
differ,  the  more  is  light  bent  in  passing  from  one  object  to 
another. 

438.  There  are  therefore  two  things  which  influence  the 
bending  of  light.     1.   The  direction  in  which  it  falls  upon  an 
object.     2.   The  density  of  the  object. 


152  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II, 

439.  If  now  light  pass  in  straight  lines  through  the  flat  piece  of  glass 
C  (Fig.  57),  it  does  not  change  its  course  because  it  falls  upon  the  glass 
perpendicularly  to  the  surface,  but  when  the  light  passes  to  the  piece  of 
glass  L,  made  with  rounded  surfaces,  the  light  will  be  bent  as  it  enters 
the  glass,  because  it  does  not  strike  upon  the  glass  L,  perpendicularly  to 
its  surface.  It  will  of  course  be  bent  towards  the  perpendicular  to  the 
surface  it  is  entering.  When  it  has  passed  through  the  glass  and  enters 
the  air  it  will  be  bent  from  the  perpendicular,  because  it  is  entering  a 
less  dense  object  than  it  is  leaving.  The  result  is  seen  from  the  figure. 

Fig.  57. 


Fig.  57. — a,  6,  c,  represent  rays  of  light  which  pass  through  the  piece  of  glass  c, 
without  being  bent  as  they  fall  perpendicularly  upon  the  glass  c.  But  as  they  fall  upon 
the  lens  L,  in  a  direction  not  perpendicular  to  its  surface,  they  are  bent  in  such  a  man- 
ner that  they  all  cross  each  other  at  the  point  ra,  which  is  called  the  focus,  beyond  the 
focus  the  rays  spread  farther  and  farther  from  each  other. 

440.  The  principle  is  perhaps  better  illustrated  by  Fig.  58  : — a  rep- 
resents a  candle,  with  the  ray  of  light  (a,  d)  passing  to  a  piece  of  glass 
(d,  k)  called  a  lens.  As  soon  as  the  light  enters  the  lens,  it  is  bent 
towards  the  perpendicular  (e,  d)  to  the  surface  it  is  entering.  When  the 
light  passes  from  the  lens,  the  light  is  again  bent,  and  is  now  bent  from 
the  perpendicular  (h,  g~)  to  the  surface  of  the  air  it  is  entering,  and  passes 
on  in  the  straight  line  (h,  i)  until  it  shall  meet  some  object  which  will 
absorb  it,  reflect  it,  or  transmit  it.  Again,  the  light  (c,  k),  as  it  enters 
the  lens,  is  bent  toward  the  perpendicular,  and  when  it  leaves  the  lens 
is  of  course  bent  from  the  perpendicular,  and  goes  on  in  the  straight  line 
(k,  i)  till  it  meet  some  object.  Observe  now  an  important  thing :  the 
light  (a,  d,  h,  i)  crosses  the  light  (c,  k,  i)  at  a  point  (i),  which  is  called 
a  focus  ;  and  it  will  be  seen  by  Fig.  57,  that  all  the  light  passing  to  the 
lens  between  the  outer  rays  (a,  and  c)  will,  by  the  application  of  the 
principles  just  mentioned,  be  bent  so  as  to  cross  at  the  same  point  or 
focus  (m). 


Fig.  53.— «,  6,  c,  are  three  rays  of  light  falling  upon  a  lens;  (6,/)  falling  per- 
pendicularly  upon  its  surface  is  not  bent  upon  entering,  and  as  it  leaves  in  a  line  per- 
pendicular to  the  surface  it  is  not  bent.  The  line  a,  falling  at  d  upon  the  lens  to  which 

e,  d  is  perpendicular,  is  bent  toward  that  part  of  the  perpendicular  within  the  lens 
which  the  light  is  entering.    When  the  light  leaves  the  lens  at  A,  instead  of  passing  to 

f,  it  is  bent  from  the  perpendicular  /«,  g,  to  the  point  i.     It  is  understood  that  the  light 
is  passing  from  the  lens  into  a  less  dense  substance. 

441.  The  problem  is  then  solved,  viz.,  if  the  light  coming 
from  any  point  be  made  to  pass  through  a  substance  of  proper 
nature  and  form,  it  will  be  gathered  to  a  point. 

In  proof  of  this,  let  the  reader  try  the  effect  of  a  sunglass,  which  is 
a  simple  lens,  the  surfaces  of  which  are  rounded  or  convex.  If  the  light 
of  the  sun  be  allowed  to  shine  upon  the  sunglass,  and  a  piece  of 'paper 
or  any  object  be  held  upon  the  other  side  of  the  lens,  by  moving  the  ob- 
ject nearer  or  farther  from  the  lens,  at  last  it  will  be  seen  that  the  lens 
bends  all  the  light  falling  upon  it  in  such  manner  that  the  light  crosses  at 
a  point.  For  if  an  object  should  be  held  in  the  light  at  the  points  1, 2,  3, 
Fig.  57,  it  would  make  a  smaller  spot  at  2  than  at  1,  and  a  smaller  one 
still  at  m,  and  a  larger  one  again  at  4,  just  as  the  light  passing  through  the 
lens  does  upon  the  object  held  in  its  course  ;  for  if  this  be  held  quite  near 
to  the  lens,  and  then  withdrawn  slowly,  the  light  will  produce  a  smaller 
and  brighter  spot,  till  at  last  there  is  a  mere  point,  when  the  spot  will  in- 
crease in  size  and  dimmish  in  brightness.  If  the  experiment  be  tried 
with  the  light  of  a  candle  and  sunglass,  the  result  will  be  the  same. 

442.  Suppose  now,  there  are  two  points  at  a  little  distance  from 
each  other,  as  in  Fig.  59,  A,  B,  from  which  light  is  passing  to  a  lens. 
By  the  application  of  the  before-mentioned  rules,  the  light  will  be  found 
mingled  on  the  front  surface  of  the  lens,  but  so  bent  as  it  enters  the  lens 
and  passes  from  it,  that  all  the  light  from  A,  which  falls  upon  the  lens, 
crosses  at  the  point  b,  and  all  the  light  from  B  crosses  at  a.  If  an  ex- 
periment be  tried  with  a  sunglass  and  two  or  more  candles,  the  same 
thing  will  be  proved,  for  it  will  be  found  that  all  the  light  from  each  can- 
dle will  cross  at  the  same  spot  it  will  if  that  candle  only  be  lighted.  Of 

7* 


154  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II, 

course,  if  the  object  receiving  the  light  be  held  in  the  right  place,  the  light 
passing  through  the  lens  will  produce  as  many  spots  as  there  are  candles. 

Fig.  59. 


Fig.  59.— A,  B,  repres 
the  light  falls  upon  the  c< 
iris ;  E,  E,  the  lens,  the 


>.— A,  B,  represent  two  points,  of  which  there  may  be  millions.    From  A,  B, 
'     cornea,  c,  c,  and  is  bent  as  it  is  passing  into  the  eye.    D,  is  the 
te  small  spot  at  which  the  central  rays  or  axes  from  A  and  B 

pass,  being  called  the  centre  of  the  lens.  After  the  light  leaves  the  lens  it  is  observed 
to  cross  at  the  retina  (a,  d),  while  if  the  retina  had  been  as  far  distant  as  G,  or  only  as 
far  distant  as  H,  the  light  would  have  acted  over  considerable  space. 


443.  If,  now,  we  go  back  to  the  subject  of  IT 428,  we  shall  readily  see 
how  to  gain  the  desired  end,  viz.,  by  placing  a  lens,  as  in  Lith.  PI.  5, 
Fig.  2,  so  that  all  the  light  passing  through  the  pupil  of  the  eye  shall  pass 
through  the  lens ;  for  by  that  means  the  light  coming  from  any  point  of 
an  object  will  cross  at  a  certain  point  within  the  eye,  and  if  the  nerve  be 
there,  it  will  be  acted  upon  by  all  the  light  coming  from  the  given  point 
of  the  object,  and  entering  the  pupil. 

444.  There  are  now  two  difficulties  to  overcome  ;    the  first  is,  what 
is  called  the  "  spherical  aberration."      It  is  produced  as  explained  by 
Fig.  60  ;    the  light  falling  upon  the  surface  of  the  lens  near  its  edges,  is 
bent  more  than  the  central  light,  because  from  the  shape  of  the  lens  the 
light  falls  more  obliquely  or  slanting  upon  the  surface  near  the  edges  than 
upon  the  more  central  parts  of  the  lens.      Of  course,  the  light  passing 
through  the  outskirts  of  the  lens  will  cross  at  a  point  or  focus  nearer  the 
lens  than  the  central  light  will ;   but  it  is  desirable  to  have  all  the  light 
cross  at  the  same  point,  and  it  must  be  so  arranged  that  all  the  light 
coming  from  any  point  of  an  object,  and  falling  upon  the  lens,  may  act 
upon  the  nerve.     This  end  is  gained  in  three  ways : 

445.  1st.  The  iris  (rainbow),  or  colored  part  of  the  eye, 


SEC.  3.] 


ORGANS  OF  SENSE. 
Fig.  60. 


155 


Fig.  60.— Exhibits  the  fact  that  A,  O,  falling  perpendicularly  on  the  lens,  is  not 
bent.  B,  6,  are  bent  somewhat,  and  cross  at  o.  C,  c,  are  bent  still  more,  and  cross  at 
h ;  while  D,  d  are  bent  most  of  all,  and  crost  at  H. 

represented  by  the  partition  a,  in  Lith.  PL  5,  Figs.  1,  2,  pre- 
vents light  from  falling  upon  the  edges  of  the  lens. 

446.  2d.  The  form  of  the  lens,  as  found  in  the  eye,  is 
peculiar,  and  such  (Fig.  61)  as  is  adapted  to  the  purpose 
desired,  being  more  round,  or  more  convex  on  the  back  or 
posterior  surface  than  on  the  front  surface. 

447.  3d.  By  the    peculiar   structure   of  the   lens,  it  is 
adapted  to  its  purpose.     It  is  composed  of  layers  like  an 
onion,  and  as  represented  in  Fig.  61.     The  outer  layers  are 
almost  liquid,  the  next  like  jelly  in  consistence,  the  middle 
of  the  lens  being  almost  like  gum-arabic  for  density. 

The  light,  therefore,  which  passes  through  the  central  part  of  the 
lens,  will,  on  account  of  its  greater  density  towards  the  centre,  be  bent 
more  than  otherwise,  and  cross  at  the  same  point  as  the  light  passing 
through  the  outer  parts  of  the  lens. 

448.  The  second  difficulty  to  overcome  is  this :  the  different  kinds 
of  light  are  not  bent  equally  by  the  same  substance.      If  the  light 
passing  from  the  point  a,  Fig.  62,  be  white  light,  that  is,  composed  of 
the  three  kinds,  red,  yellow,  and  blue,  as  it  passes  through  a  common 


156  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP. 

Fig.  61. 


Fig.  61. — Cornea  fitted  into  the  sclerotic  coat.  A,  Choroid.  B,  Pigmentum  nigrutn- 
C.  Retina,  lined  by  the  hyaloid  membrane,  containing  (K)  the  vitreous  humor.  D» 
Tne  optic  nerve.  I,  The  lens.  G,  Iris,  coated  on  the  back  side  with  pigment,  (paint)- 
H,  Ciliary  processes.  F,  Aqueous  humor. 

lens,  it  will  be  found  that  the  blue  light  is  bent  the  most,  and  crosses  at  a 
point  nearer  to  the  lens  than  where  the  yellow  crosses,  which  is  also 
nearer  than  the  focus  of  the  red  light.  But  in  the  eye  under  ordinary 
circumstances,  this  does  not  take  place.  How  it  is  prevented  is  not 
known.  We  may  now  pass  to  consider  the  structure  of  the  eye,  and  it3 
appendages,  after  which  we  shall  be  able  to  sum  up  the  abilities  of  the 
eye,  and  have  a  clear  view  of  what  seeing  is,  and  how  it  is  accom- 
plished. 

449.  First,  the  external  appendages  of  the  eye.     The 
eye  is  placed  in  a  deep  and  large  socket.     In  this  the  eye  is 
protected  by  a  cushion  of  fat,  in  and  upon  which  it  is  situ- 
ated.    It  is  also  well  protected  from  blows  by  the  jutting 
forehead,  the  prominent  nose  and  cheek  bone;   indeed,  it  is 
shielded  in  every  direction,  except  directly  in  front  and  to 
the  outside,  where  it  can  easily  see,  not  only  to  take  care  of 
itself,  but  also  the  body. 

450.  The  eyebrows  also  shield  the  eye  in  a  measure 


SEC.  3.] 


ORGANS  OF  SENSE. 
Fig.  62. 


157 


Fig.  62. — Shows  that  some  of  the  light  is  bent  more  than  the  rest. 

from  the  dazzling  rays  of  the  sun,  and  from  the  perspiration 
flowing  from  the  forehead.  They  are  nourished  and  caused 
to  grow  by  the  blood  which  flows  around  their  roots.  To 
insure  a  good  supply  of  this,  the  skin  at  the  eyebrows  should 
be  daily  rubbed. 

451.  The  eyelids  close  over  the  eye  to  exclude  dust,  to 
wipe  off  the  dust  which  has  been  admitted,  and  to  spread  the 
fluid,  called  tear-fluid,  over  the  eye.  The  movement  of  the 
lids  is  accomplished  by  two  muscles.  One  is  called  the  an- 
nular, orbicular,  or  ring  muscle  of  the  eyelid.  It  passes 
around  the  opening  of  the  lids,  as  in  Lith.  Fig.  1,  PI.  I. 
When  it  contracts,  it  gently  closes  the  eye.  When  forcibly 
contracted,  it  slightly  draws  inward  the  outer  corners  of  the 
eyelids,  as  the  muscle  is  connected  to  the  edge  of  the  orbit 
near  the  nose.  The  eyelid  is  raised  by  a  muscle  which 
commences  at  the  back  part  of  the  eye  socket,  and  passing 
over  the  eyeball,  terminates  in  the  upper  lid  just  beneath  the 
skin,  and  above  the  edge  of  the  lid,  as  seen  in  Fig.  63.  The 
form  of  the  edge  of  the  lid  is  preserved  by  cartilages,  called 
the  tarsi.  They  are  curved  to  the  form  of  the  eyeball,  but 


158  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

keep  the  lids  stretched  from  corner  to  corner.  At  the  outer 
edge  of  the  lids  the  eyelashes  are  found  beautifully  curved, 
in  such  way  that  when  the  lids  are  closed  they  may  inter- 
lace,  yet  their  ends  be  never  entangled,  as  is  seen  in  Fig.  64. 
Sometimes  an  eyelash  will  perversely  grow  into  the  eye.  It 
should  be  drawn  out  of  the  lid  at  once,  and  if  the  one  which 
follows  it  shall  take  the  same  course,  as  it  probably  will,  that 
is  to  be  treated  in  the  same  way.  The  lashes  sometimes 
come  out,  and  either  the  disease  which  causes  them  to  come 
out,  or  their  coming  out,  produces  very  bad  results.  The 
physician  should  be  consulted  in  good  season.  The  edges 
of  the  lids  when  closed,  do  not  leave  a  groove  at  their  back 
edge,  as  sometimes  said,  and  as  represented  by  Fig.  65. 
The  lids  meet  at  the  back  edge,  but  not  at  the  front,  as  any 
person  may  satisfy  himself  by  looking  at  the  closed  eye. 
Near  the  inner  edge  of  the  lids  there  are  many  small 
openings  of  tubes,  which  lead  up  into  the  lid  and  terminate 
in  minute  pieces  of  apparatus,  consisting  of  coiled  tubes, 
called  Meibomian  glands.  In  these  is  formed  a  kind  of  fatty 
substance,  which,  oozing  down  upon  the  edges  of  the  lids, 
serves  to  prevent  the  tear-fluid  from  running  over  upon  the 
cheek. 

452.  The  tear  apparatus  consists  of  a  small  organ,  about 
the  size  and  form  of  a  sparrow's  egg,  of  a  whitish-yellow 
color ;   situated  above  the  eye,  a  little  outside  of  the  middle 
of  the  socket,  and  near  its  front  edge.     In  this,  the  tear-fluid 
is  formed  from  the  blood.     From  this,  which  is  called  the 
lachrymal  or  tear-gland1!  from  ten  to  fifteen  very  minute  tubes 
lead  down,  and  open  into  the  eye  through  the  inner  surface 
of  the  upper  eyelid,  just  above  its  inner  edge.     Through 
these,  the  eyes  are  moistened. 

453.  The  tear-fluid  is  led  off  from  the  eye  into  the  nose, 
through  appropriate  tubes.     If  the  prominent  point  of  the 
lids,  seen  near  the  inner  corner,  be  turned  out,  a  black  speck 


SEC.  3.] 


ORGANS  OF  SENSE. 


159 


Fig.  63. 


Fig.  64. 


Fig.  64. — The  left  eye  with  the  muscles  of  itself  and  lids,  exposed  by  removing  the 
outer  "part  of  the  socket,  a,  The  elevator  of  the  eyelid  (levator  palpebrarum).  b, 
The  superior,  e,  The  external,  and  c,  the  inferior  recti  (straight)  muscles,  a,  The 
inferior  oblique. 

Fig.  04.— Represents  the  eyeball  with  the  entering  nerve  at  the  back  part.  The 
curved  lids  are  seen  in  front,  and  the  skin  covering  the  lids  is  observed  to  continue 
round  the  edges  of  the  lids  to  line  them,  and  then  is  reflected  back,  as  it  is  called,  upon 
the  eyeball,  over  the  cornea,  and  is  continuous  with  the  lining  of  the  lower  lids. 

Fig.  65. 


will  be  readily  noticed.  Upon  further  examination,  it  is 
found  to  be  the  opening  of  a  minute  tube,  which  curves 
around,  and  with  its  fellow  from  the  other  lid,  opens,  as 
seen  in  Fig.  66,  into  a  large  tube  or  canal,  called  the 
lachrymal  or  tear-duct.  This  opens  into  the  nose. 

454.  The  tears  are  of  use,  ordinarily,  to  moisten  the  eye,  and  after- 
wards the  nose.     When  horseradish,  mustard,  and  such  things,  "  fly  up 
into  the   nose,*'   the  flow  of  tears  is  increased  in  such  a  degree  that 
they  cannot  be    carried   off  into   the   nose,  but   gush   over   upon   the 
cheek.     The  intention  in  this  case  is,  that  by  flowing  into  the  nose  they 
shall  remove  the  substances  producing  the  trouble.     The  flow  of  tears  is 
often  increased  by  the  emotions.    Their  use  in  these  cases  is  not  evident. 

455.  The  tubes  leading  from  the  eye  to  the  nose,  are  sometimes 
closed ;  the  tears  then  constantly  flow  over  upon  the  cheek,  and   the 
person  by  constantly  wiping  them  away  brings  on  soreness  of  the  eye, 
which,  in  a  little  time,  becomes  very  distressing  and  serious.     A  slight 
operation  of  inserting  a  small  silver  tube  will  remedy  the  whole  evil.     It 


160  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP. 

Fig.  66. 

^-rz 

A, 


Fig.  66.— A,  represents,  but  not  correctly  as  it  respects  form,  the  lachrymal  or  tear- 
gland  ;  B,  the  ducts  or  tubes  leading  from  A,  into  the  eye ;  C,  C,  the  puncta  lachry- 
malia,  or  the  openings  through  which  the  tears  flow  from  the  eye  into  D,  the  lachrymal 
or  tear-sac,  which  opens  at  E,  into  the  nose. 

may  result  from  a  cold,  and  pass  away  when  the  cold  is  removed.     If  it 
do  not,  let  it  be  early  attended  to. 

456.  The  lining  of  the  eyelids  and  the  covering  of  the  eye- 
ball, are  very  similar  in  their  nature  to  the  lining  of  the 
nose  ;  indeed,  may  be  considered  as  a  part  of  the  same 
thins;  extending  through  the  tubes  which  connect  the  eyes 
and  nose. 

It  is  therefore  seen,  how  liable  the  lining  of  the  eye  will  be  to  dis- 
ease, if  a  person  take  cold  ;  both  on  account  of  its  similar  structure  with 
the  lining  of  the  nose,  and  from  its  intimate  connection  with  it.  In 
ordinary,  slight  inflammation  of  the  eye,  experience  has  long  proved 
there  is  nothing  so  generally  good,  as  washing  the  eyes  frequently  with 
cold  water.  From  the  similarity  of  structure,  it  might  be  assumed  that 
similar  benefit  would  ensue  from  bathing  the  nostrils  with  cold  water,  by 
snuffing  it.  This  is  found  to  be  the  case  in  colds,  catarrhs,  &c.  All 
those  eye-washes,  lauded  so  highly  by  their  cowscienceZess-compounders 
and  venders,  should  be  carefully  avoided.  If  good  for  any  thing,  they  can- 
not be  worth  what  will  be  charged  for  them,  and  many  a  man  has  lost 
his  eye-sight  by  the  use  of  them,  when  he  thought — if  they  did  no  good, 
they  would  do  no  harm.  An  inflamed,  or  sore  condition  of  the  eye, 


SEC.  3.]  ORGANS  OF  SENSE.  161 

should  not  be  neglected  as  it  is,  too  frequently,  but  attended  to  by  some 
one  who  is  responsible. 

457.  At  the  inner  corner  of  the  eye,  and,  as  it  were,  be- 
tween the  ball  and  the  inner  corner  of  the  lids,  is  a  substance 
or  part — small,  but  somewhat  prominent.     It  is  of  a  pale  red 
in  ill  health,  and  a  bright  red  in  health.    Upon  its  surface  are 
the  openings  of  small  tubes,  leading  to  an  apparatus  like  the 
Meibomian  glands,  forming  in  considerable  quantities  a  simi- 
lar substance,  which  at  times  is  seen  collected  at  the  inner 
corner  of  the  eye.     On  the  surface  of  this  is  seen,  upon 
examination,  a  number  of  very  minute  hairs ;   which  some- 
times become  large,  and  prove  very  troublesome — irritating 
the  eye,  &c.     This  must  be  prevented  by  drawing   them 
out,  and  repeating  the  operation  as  often  as  necessary. 

From  the  inner  corner — though  not  from  the  part  just  described — 
a  fleshy  substance  sometimes  grows,  and  extends  up  over  the  ball  of  the 
eye.  If  this  growth  be  very  slow,  hardly  observable  from  year  to  year' 
and  cause  no  soreness,  it  may  be  let  alone.  But  if  it  grow  fast,  and 
extend  up  to  the  transparent  part  of  the  ball,  and  threaten  to  cover  "  the 
sight "  or  any  part  of  it,  it  should  be  removed  at  once  ;  and  if  it  grow 
again,  as  is  probable,  it  should  be  again  removed. 

458.  The  ball  of  the  eye  is  moved  -  by  the  action  of  six 
muscles.     Five  are  attached  (Fig.  67)  by  one  extremity,  to 
the  deepest  part  of  the  socket ;  four  of  the  five,  called  recti 
or  straight  muscles — as  their  name  would  indicate — come 
forward  in  a  straight  direction  and  are  attached  to  the  white 
of  the  eye,  just  back  of  its  front  edge. 

One  muscle  is  attached  above  ;  one  beneath  on  the  outside,  and  one 
on  the  inside.  The  contraction  of  these  muscles  draws  the  eye  either 
upward,  downward,  outward,  or  inward  ;  and  two  muscles  acting  at  the 
same  time,  direct  the  eye  in  the  intermediate  direction — while  the  suc- 
cessive contraction  of  the  muscles,  will  produce  a  rotary  motion  of  the  eye. 

459.  The  fifth  muscle,  called  the  superior  oblique,  passes 
forward  (as  seen  in  Fig.  67)  to  near  the  upper  edge  of  the 
socket,  and  nearer  the  nose  than  the  centre  of  the  socket, 


162  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

Fig.  67. 


Fig.  67.— 1,  A  small  portion  of  the  bottom  or  back  part  of  the  socket  of  the  eye.  2, 
The  optic  nerve.  3,  The  eyeball.  4,  The  levator  of  the  eyelid,  with  eyelashes  at- 
tached. It  is  raised  up  from  its  natural  position — to  show,  5,  The  superior  oblique 
passing  through  the  tendinous  loop  6.  7,  Being  a  continuation  of  the  tendon  5,  and  is 
attached  to  the  eyeball  near  3.  8,  Is  the  tendon  of  the  inferior  oblique,  attached  to  a 
piece  of  bone  which  forms  part  of  the  eye-socket  near  the  roots  of  the  nose.  9,  The 
superior  rectus.  10,  The  internal  rectus.  11,  12,  The  external  rectus,  with  a  portioa 
cut  out  that  other  parts  may  be  shown.  13,  The  inferior  rectus.  14,  The  edge  of  the 
eclerotic,  where  it  is  joined  to  the  cornea. 


where  the  tendon  of  the  muscle  passes  through  a  tendinous 
loop,  when  it  turns  back  and  becomes  attached  to  the  upper, 
outer,  and  back  part  of  the  eyeball.  When  this  muscle 
contracts,  therefore,  it  rolls  the  eye  inward  and  down,  as 
when  the  eye  is  directed  to  the  tip  of  the  nose. 

460.  The  sixth  muscle,  called  the  inferior  oblique,  is  at- 
tached by  one  extremity  to  the  front  and  lower  part  of  the 
socket  near  to  the  nose.  It  then  passes  under  the  eyeball 
and  becomes  attached  to  it  at  its  lower,  outer,  and  back  part. 
When  it  contracts,  it  tends  to  roll  the  eye  upward  and  out- 
ward, causing  it  to  look  toward  the  outer  end  of  the  eyebrow. 

461.  It  is  thought  that  the  contraction  of  the  inferior  and  superior 
oblique  muscles  would  tend  to  draw  the  eye  forward,  while  the  recti 
muscles  by  contracting  would  tend  to  draw  the  eye  backward,  thus  sus- 
pending the  eye  as  it  were,  and  causing  it  to  be  moved  with  the  greatest 
ease. 

462.  Sometimes  one  eye  or  both  are  drawn  inward,  sometimes  out- 
ward.    At  one  time  it  was  thought  that  this  was  owing  to  the  inner 
or   outer   muscle   being    imperfect — too  short.     Very  many  operations 
were  therefore  performed  of  cutting  the  muscle,  supposed  to  be  too  short. 
But  it  was  found  to  remedy  the  evil  in  only  a  few  cases.     The  cause 


SEC.  3.]  ORGANS  OF  SENSE.  168 

of  the  evil  was  discovered,  upon  examination,  to  be  a  defect  in  the  power  of 
seeing,  with  the  eye  which  was  turned  out  of  its  natural  position  that  it 
might  not  interfere  with  the  vision  of  the  other.  Sometimes  this  defect 
is  removed  by  the  operations  of  nature,  when  in  some  cases  the  eye  re- 
turns to  its  natural  action,  but  in  some  cases  does  not.  In  these  cases, 
and  in  those  where  the  muscles  are  naturally  too  short,  it  will  be  proper 
to  operate  by  cutting  the  muscle,  the  cut  ends  of  which  will  be  in  a 
short  time  connected  by  an  additional  quantity  of  substance,  which  will 
make  an  addition  to  the  length  of  the  muscle.  But  if  the  eye  be  defect- 
ive, the  muscle,  true  to  its  duty,  will  again  direct  the  sight  of  the  eye 
inward.  If  a  child  be  cross-eyed,  the  eyes  should  be  examined,  and  if 
the  vision  be  defective,  let  the  mother  remember  that  a  good  disposition 
and  a  cultivated  mind  will  make  her  daughter  more  happy  and  more 
loved,  and  the  means  of  more  happiness  to  others,  than  if,  without  these, 
she  were  gifted  with  the  fabled  beauty  of  the  Houries. 

463.  The  eye.  The  outer  part  of  the  eyeball,  from  its 
color,  is  called  the  "  white  of  the  eye,"  and  from  its  firmness 
is  called  the  sclerotic  (hard)  coat.  It  has  two  openings,  a 
large  one  in  front,  to  admit  light,  and  a  much  smaller  one,  a 
little  to  the  inside  of  the  back  centre,  to  admit  a  bundle  of 
nerves,  called  collectively  the  optic  (to  see  with)  nerve. 
From  the  form  and  structure  of  the  sclerotic  it  yields  but 
slightly,  except  to  great  pressure.  It  is  about  the  thickness 
of  common  pasteboard,  thicker,  however,  at  the  back  than  the 
front  part. 

The  use  of  this  spherical  box,  is  to  allow  the  attachment  of  muscles, 
the  action  of  which  properly  direct  the  "  sight  of  the  eye  ;"  to  allow  the 
nerves  to  enter  from  the  brain,  and  the  light  which  is  to  act  upon  them,  to 
enter  from  the  world  ;  and  to  preserve  from  harm  the  delicately  adjusted 
apparatus,  which  causes  the  light  from  any  point  of  an  object  to  act  on 
the  point  of  a  single  nerve.  Sometimes  the  sclerotic  is  misshapen,  for  it 
is  seen  by  Lith.  Fig.  2,  PI.  5,  that  a  certain  size  of  box  is  necessary,  that 
the  focus  of  the  light  passing  through  the  lens  may  be  on  the  end  of  a 
nerve,  found  in  the  back  part  of  the  box.  Sometimes  the  sclerotic  is 
too  deep,  sometimes  not  deep  enough.  The  remedy  for  this  is  wearing 
glasses,  as  hereafter  shown.  Sometimes  the  back  part  of  the  sclerotic 
is  not  perfectly  well  shaped,  being  irregular,  in  which  case  vision  will  be 
confused — for  this  there  is  no  remedy. 


164  ORGANS  OF  SENSATION  OR  FEELING.  [cHAP.  II. 

The  sclerotic  is  rarely  subject  to  disease,  but  is  frequently  the  cause 
of  much  pain  when  the  parts  within  it  are  diseased.  It  is  painful  when 
pressed  upon,  for  this  is  a  danger  to  which  it  is  exposed,  and  which  it 
is  to  resist.  It  does  in  one  way  resist  by  the  pain  it  produces,  thereby 
calling  the  assistance  of  the  mind  to  its  relief.  This  may  be  tried  by 
making  pressure  with  the  ringer  upon  the  eye.  When  the  eye  from 
disease  is  unnaturally  full,  as  it  would  usually  be  in  case  of  inflammation 
of  any  portion  of  the  interior  apparatus,  the  pressure  made  upon  the  scle- 
rotic Will  cause  a  deep  ache,  becoming  more  severe  as  the  cause  acts 
more  powerfully.  To  avoid  using  the  eye,  and  to  make  application  of 
cold,  will  be  advisable.  But  the  attention  of  the  experienced  physician 
had  better  not  be  neglected  too  long. 

464.  Lining  the  sclerotic,  but  scarcely  adhering  to  it,  and 
not  reaching  as  far  forward  as  it  does,  will  be  found  a  more 
delicate  coat,  or  layer,  called  the  choroid,  the  explanation  of 
which  conveys  but  little  if  any  idea  of  the  thing  named.     It 
is  not  half  as  thick  as  the  outer  coat  of  the  eye.     The  sur- 
face next  the  sclerotic  is  a  rich  chocolate  brown,  while  the 
inner  surface  is  a  deep  black,  that  is,  absorbs  all  the  light 
falling  upon  it. 

The  use  of  the  choroid  is  to  form  a  support  to  the  bloodvessels, 
some  of  which  extend  forward  to  nourish,  and  supply  the  wants,  of  the 
front  parts  of  the  eye  ;  and  to  form  the  coloring  matter,  of  especial  use 
upon  its  inner  surface.  Being  the  seat  of  many  bloodvessels,  it  is  es- 
pecially liable  to  diseases  of  an  inflammatory  character,  the  treatment  of 
which  depends  upon  so  many  circumstances,  that  the  most  skilful  physi- 
cian will  sometimes  be  in  doubt.  Ignorance  only,  will  feel  assurance, 
and  promise  uniform  success. 

465.  The  coloring  matter  upon  the  inner  surface  is  so 
conspicuous,  it  is  many  times  considered  as  constituting  a  dis- 
tinct coat,  called  the  pigmentum  nigrum  (black  paint).     It  is 
very  much  thicker  as  it  is  examined  at  the  middle  and  front 
part  of  the  choroid  and  its   appendages,  than  at  the  back 
part. 

The  use  of  this  part  is  supposed  to  be  to  absorb  the  light,  which 
might  be  reflected  from  one  part  of  the  eye  to  another,  and  produce  indis- 


SEC.  3.]  ORGANS  OF  SENSE.  165 

tinct  vision,  as  is  evident  would  be  the  case  if  the  light  coming  from  one 
point  of  an  object,  were  allowed  to  be  reflected  about  till  it  should  fall 
upon  the  domain  of  another  object. 

466.  Within  the  last  mentioned  coats  is  found  the  nervous 
coat  called  the  retina  (net-w&rk,  from  the  supposed   arrange- 
ment of  the  nerves  when  the  name  was  given,  a  wrong  idea, 
however).     This  is  merely  the  divisions  and  terminations  of 
the  optic  nerve,  or  rather  it  is  the  commencing  points  of  the 
optic  nerve,  which  as  it  leaves  the  eye,  is  doubtless  com- 
posed of   all  the  filaments  commencing  at  the  millions  of 
nervous  points  presented  in  the   eye,  to  the  action  of  the 
light.     A    few  of  these  are  represented  ir\  Fig.  53.     The 
retina  is  composed  of  a  slight   amount  of  other  substance, 
serving  to  connect  the  nervous  substance. 

The  use  of  the  commencements  of  the  nerves  is  to  receive  the  action 
of  light,  the  different  kinds  of  which,  by  producing  different  effects, 
cause  different  sensations.  The  use  of  such  a  form  as  exists  in  case 
of  the  retina  will  be  seen  if  the  experiment  of  the  sunglass  with  several 
candles  be  tried.  The  candles  may  be  in  a  line,  but  the  foci  on  the 
other  side  of  the  lens  will  not  be  found  in  a  line,  but  it  will  be  necessary 
to  curve  the  objects  upon  which  the  foci  are  caught.  It  is  also  seen  in 
Lith.  PI.  5,  Fig.  2,  that  the  foci  produced  by  light  passing  through  a  lens, 
are  not  in  a  straight  line,  but  in  a  curve.  The  peculiar  form  of  the  eye 
in  respect  to  all  its  parts,  is,  of  course,  explained  in  the  same  manner. 
Thus,  there  must  be  the  most  beautiful  and  perfect  adaptation  of  the 
various  parts  of  the  eye,  both  in  their  absolute  and  proportional  size 

467.  Within  the  retina,  and  filling  nearly  two-thirds  of 
the  cavity  of  the  eyeball,  is  found  what  is  called  the  vitreous 
(glass-like,  not  from  its  being  as  solid,  but  from  its  being 
transparent  as  glass)  humor.     It  is  composed  of  a  membrane 
called  hyaloid,  (glass-like,  from  being  very  pellucid)  which 
covers  it  entirely,  and  is  arranged  through  it  in  the  form  of 
cells,  which  are  filled  with  a  very  limpid  fluid.     The  mem- 
brane does  not  adhere  to  the  retina  at  all,  but  is  connected 
with  the  choroid  at  its  front  part,  by  processes  adapted  to  the 


166  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

purpose.  At  its  front  part,  it  is  hollowed  out,  or  concave, 
to  receive  the  back  part  of  the  lens,  as  represented  in  Fig. 
61.  Between  the  hyaloid  and  retina,  but  belonging  to  the 
retina,  is  found  a  network  of  bloodvessels,  formed  by  the 
divisions  of  a  bloodvessel,  which  enters  the  eye  through  the 
centre  of  the  nerve.  One  branch  of  it  extends  through  the 
centre  of  the  vitreous  humor. 

The  network  upon  the  retina  is  represented  by  Fig.  68,  and  may  be 
seen  by  closing  one  eye  and  directing  the  other  immovably  upon  some 
object  like  a  white  wall,  and  moving  a  candle  up  and  down  near  to  the 
eye,  upon  dther  side. 

Fig.  68. 


Fig.  68. — The  artery  and  its  coarser  branches  found  at  the  back  part  of  the  eya 
upon  the  retina. 

The  use  of  the  hyaloid,  and  the  fluid  it  contains,  is  to  fill  the  back 
part  of  the  eye  with  a  substance  which  shall  act  in  such  a  manner  upon 
the  light  leaving  the  lens,  that  it  shall  produce  a  proper  effect  upon  the 
nerve.  But  as  light  is  acted  upon  differently  by  objects  differing  in  their 
density,  the  proper  action  of  the  vitreous  humor  will  depend  upon  its 
being  of  a  proper  density.  If  it  be  too  dense,  it  will  bend  the  light 
too  much,  and  its  focus  will  not  be  on  the  nerve,  but  near  to  the  lens. 
If  the  vitreous  humor  be  not  sufficiently  dense,  the  light  will  not  be  bent 
enough,  and  the  focus  will  not  be  at  the  nerve,  but  the  light  will  fall 
upon  the  nerve  before  it  has  arrived  at  its  focus.  In  either  case,  vision 
will  be  indistinct.  The  density  of  the  vitreous  humor  depends  upon  the 
hyaloid  membrane  forming  the  cells,  and  the  fluid  filling  them.  Either 
of  these  parts  may  vary  in  respect  to  their  density.  The  evil  of  either 
kind  is  to  be  corrected  by  wearing  proper  glasses.  But  either  the  mem- 
brane or  the  fluid  may  lose  its  transparency  in  whole  or  in  part,  in  which 


SEC.  3.]  ORGANS  OF  SENSE. 

case,  as  the  light  cannot  pass  through  perfectly,  more  or  less  indistinct- 
ness of  vision  will  be  the  result.  Sometimes  this  state  is  lasting,  while  in 
other  cases,  a  proper  attention  to  health  and  the  means  for  improving 
it,  will  be  effectual.  Most  usually  all  attempts  to  improve  vision,  in 
such  cases,  will  fail. 

468.  What  has  been  said  of  the  lens  need  not  be  re- 
peated. It  is  situated  in  front  of  the  vitreous  humor,  a  pait 
of  it  sinking  into  the  concavity  of  the  humor.  It  does  not, 
however,  adhere  to  the  hyaloid  membrane,  but  is  kept  in  its 
place  by  appendages  connecting  it  with  the  choroid,  similar 
to  the  appendages  which  connect  the  hyaloid  with  it.  They 
are  called  ciliary  (like  the  eyelashes)  processes.  They  do 
not,  however,  resemble  them,  but  more  resemble  a  plaited, 
narrow  ribbon.  The  lens  is  composed  of  a  capsule,  or 
covering,  and  the  substance  contained  within,  differing  in 
density  as  the  centre  is  approached. 

The  use  of  the  lens  has  been  already  set  forth.  But  its  use  has  been 
somewhat  exaggerated,  as  it  has  been  made  to  represent  the  entire  ap- 
paratus, which  causes  the  light  to  be  properly  bent.  It  does  not  per- 
form all  this  duty  ;  indeed,  it  does  not  perform  the  most  important  part 
of  it.  It  bends  the  light  somewhat,  but  its  greatest  probable  use  is 
owing  to  the  different  densities  of  its  parts,  as  it  thus  corrects  the  sphe- 
rical aberration.  Its  form,  also,  assists  in  the  same  matter. 

As  the  utility  of  the  lens  is,  however,  to  bend  the  light,  to  a  greater 
or  less  degree,  a  greater  or  less  density  of  the  lens  must  affect  its  mode 
of  action.  If  more  dense  than  it  should  be,  it  will  bend  the  light  more 
than  it  should  ;  if  less  dense  than  it  should  be,  it  will  not  bend  the  light 
enough.  In  either  case,  as  seen  in  the  case  of  the  vitreous  humor,  the 
focus  will  not  be  at  the  nervea  The  evil  must  be  remedied  by  the  use 
of  glasses.  If  the  different  densities  of  the  parts  of  the  lens  from  the 
circumference  to  the  centre  are  not  what  they  should  be,  vision  must  be 
indistinct.  If  the  central  part  be  not  so  dense  as  it  should  be  in  propor- 
tion to  the  outskirts  of  the  lens,  the  light  passing  through  the  centre  will 
not  be  brought  to  a  crossing  point  so  soon  as  the  light  passing  through 
the  outskirts,  and  vice  versa,  as  seen  in  Fig.  62. 

The  capsule  of  the  lens  is  liable  to  diseases  of  various  kinds,  by  some 
of  which  it  becomes  thickened,  or  loses  its  transparency.  The  same  is 


168  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

true  of  the  substance  of  the  lens.  A  thick,  milky  appearance  of  the 
lens,  produces  what  is  called  a  cataract.  In  these  cases,  the  light  not 
passing  through  the  lens,  vision  is  impossible  or  very  imperfect.  Some- 
times the  physician  is  able  to  remove  the  diseases  of  these  parts ;  but  to 
restore  sight,  it  is  usually  necessary  to  remove  the  lens.  This  is  called 
an  operation  for  the  cataract.  It  is  not  very  painful,  and  almost  always 
has  a  favorable  termination.  Glasses  must  be  worn,  as  it  is  necessary 
for  a  lens  outside  the  eye  to  do  that  for  which  the  removed  lens  was  in- 
tended. 

469.  We  will  now  pass  to  the  cornea.  This  is  fitted  into 
the  sclerotic  coat  much  as  a  crystal  of  a  watch  is  fitted  in 
its  case,  as  seen  in  Fig.  61.  It  forms  the  front  part  of  the 
eyeball.  It  is  more  prominent  than  the  sphere  would  be,  to 
which  the  sclerotic  belongs,  as  is  easily  felt.  It  is  perfectly 
transparent,  as  is  the  delicate  skin  or  membrane  covering  it, 
and  which  is  a  continuation  of  the  skin  lining  the  lids  and 
covering  the  front  part  of  the  sclerotic,  as  seen  in  Fig.  64. 
If  put  in  alcohol,  the  outer  part  of  the  cornea  becomes  milky 
in  color,  while  the  inner  part  remains  clear  as  before.  This 
shows  that  the  cornea,  though  it  be  thin,  is  composed  of  seve- 
ral layers,  differing  in  their  nature.  It  may  be,  that  in  this 
way  the  eye  obtains  its  "  achromatic  "  properties. 

The  use  of  the  cornea  is  almost  evident.  It  serves  as  a  window 
to  admit  light.  But  as  light  must,  from  the  convex  surface  of  the  cor- 
nea, enter  it  for  the  most  part  in  a  slanting  or  oblique  direction,  it  will 
bend  the  light,  and  very  much  likewise,  because  the  difference  in  the  den- 
sity of  the  cornea  and  the  air  from  which  the  light  comes  is  great.  It  is 
here  indeed  that  the  bending,  or  refraction,  as  it  is  called,  of  the  light, 
is  greater  than  any  where  else  in  the  eye.  But  the  density  of  the  cor- 
nea may  vary,  when  the  effect  it  will  have  upon  the  light  will  be  corres- 
pondent, and  cause  its  focus  to  fall  somewhere  besides  on  the  nerve. 
The  bending  of  the  light  will  depend  also  upon  its  form.  The  more 
round  or  convex  it  is,  the  more  will  it  bend  or  refract  the  light. 

The  cornea,  or  the  membrane  covering  it,  may  be  affected  with  vari- 
ous diseases,  in  the  course  of  which  their  transparency  may  be  in.  part  or 
wholly  lost.  It  can  sometimes  be  regained  by  proper  treatment ;  some- 
times it  cannot.  The  covering  of  the  cornea  is  so  delicate,  it  is  very 


SEC.  3.]  ORGANS  OF  SENSE.  169 

hazardous  to  operate  on  it  with  carelessly  made  eye-washes — made  only 
to  sell,  and  generally  by  irresponsible  persons. 

470.  Between  the  cornea  and  lens  is  a  space  filled  with 
fluid  of  a  very  limpid  character,  called  the  aqueous  (water- 
like)  humor.     It  is  less  dense  than  the  cornea,  and  of  course 
an  effect  will   be  produced  on  the  light  entering  the  humor, 
but  the  difference  is  very  slight,  and  the  effect  also.     The 
difference  between  it  and  the  lens  is  greater,  and  of  course 
the  light  is  acted  upon  accordingly. 

The  particular  use  of  this  fluid  is  not  evident,  except  it  be  to  fill  the 
space  with  a  fluid  in  which  the  iris  could  act  with  perfect  ease,  and  which 
by  its  nature  was  perfectly  adapted  to  receive  the  light  from  the  cornea, 
and  pass  it  in  a  proper  manner  to  the  lens. 

It  is  liable  to  become  more  or  less  dense  than  natural,  when  its 
defects  must  be  supplied  with  glasses.  It  also  sometimes  loses  its 
opacity,  which  it  can  regain,  as  a  general  thing.  Its  loss,  as  when  the 
eye  is  cut,  is  very  quickly  restored. 

471.  The  iris  corresponds  to  the  partition  a  in  Lith.  Fig. 
1,  2,  PL  5.     It  is  the  colored  part  of  the  eye.     The  opening 
is  called  the  pupil ;  circular  muscular  fibres  about  the  pupil, 
by  contraction  lessen  the  size  of  the  pupil,  (Fig.  69).      Ra- 
diating fibres,  by  contracting,  enlarge  the  pupil,  (Fig.  70). 
The  iris  divides  the  front  part  of  the  eye  into  two  chambers, 
which  communicate  with  each  other  through  the  pupil. 

Fig.  69.  Fig.  70. 


pig.  69. — A  front  view  of  the  iris,  showing  the  circular  fibres  about  the  pupiL 
Pig.  70. — A  back  view  of  the  iris,  showing  the  radiated  fibres. 

Th«  us«  of  the  iris  is  to  admit  a  greater  or  kss  number  of  rays  of 
8 


170  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

light,  and  to  prevent  light  from  passing  through  the  lens  too  near  its 
edge. 

Sometimes  at  birth,  there  is  no  opening  through  the  iris.  In  this 
case  it  is  but  a  slight  operation  to  make  one.  Sometimes  the  power  of 
enlarging  or  diminishing  the  pupil  is  lost.  This  evil  can  usually  be 
remedied  by  the  physician.  Sometimes  the  iris  is  injured  or  affected  by 
disease,  or  naturally  is  in  such  a  state  that  an  artificial  pupil  must  be  worn 
upon  the  eye.  There  are  various  diseases  of  the  iris  not  worth  while  to 
mention,  as  they  occur  but  seldom,  and  can  always  be  best  managed 
by  the  skilful  practitioner. 

472.  Thus  it  is  seen  that  all  parts  of  the  eye,  from  the  cornea  to  the 
retina,  and  also  the  sclerotic,  by  its  form  and  size,  have  an  influence  in 
producing  the  grand  result,  so  frequently  stated  as  necessary  to  be  accom- 
plished by  the  eye,  viz.,  to  cause  all  the  light  coming  from  any  one  part 
of  an  object  to  fall  upon  a  single  nerve  and  produce  an  impression,  un- 
influenced by  light  coming  from  any  other  point ;  for  the  instant  the 
light  from  any  two  objects  falls  on  the  same  nerve,  that  instant  they 
become  one  object,  for  all  power  of  distinguishing  them  is  lost.     For  if 
(Lith.  Fig.  6,  PL  5)  the  light  from  r,  b,  act  on  two  nerves,  the  light 
from  r  being  red,  and  the  light  from  b  being  blue,  will  each  produce 
its  peculiar  sensation.     But  if  the  nerves  be  considered  as  one,  the  effect 
on  it  will  cause  the  sensation  of  purple,  and  the  light  will  not  then  appear 
to  come  from  two  objects,  one  yellow  the  other  blue,  but  from  one  object 
entirely  purple. 

473.  Suppose,  however,  the  objects  r,  b,  be  brought  so  near  each 
other  as  to  act  on  the  end  of  the  same  nerve,  when  small,  as  first  sup- 
posed, or  as  represented  in  Lith.  PI.  5,  Fig.  5,  that  instant  they  will  ap- 
pear but  one,  and  cause  the  sensation  of  purple.     This  is  what  occurs 
when  paints  are  mixed — suppose  red  and  blue.      The  light  falls  upon 
them  and  is  reflected,  and  the  particles  of  red  and  blue  are  at  a  dis- 
tance from  each  other  when  the  mixing  is  commenced  ;   the  light  from 
the  different  particles  is  reflected  into  the  eye,  and  acts  on  the  end  of 
different  nerves ;  but  as  the  particles  are  brought,  by  the  process  of  mix- 
ing, nearer  and  nearer  to  each  other,  the  light  from  two  different  parti- 
cles falls  on  the  same  nerve,  and  the  two  paints  produce  the  sensation  of 
purple.      If  now,  the  nerves  of  a  person  should  be  comparatively  large, 
the  Tight  from  the  particles  of  blue  and  red  paint  would  act  on  the 
same  nerve  before  they  were  as  near  each  other  or  were  as  thoroughly 
mixed,  as  in  case  of  a  person  whose  nerves  were  finer.     Without  doubt, 


SEC.  3.]  ORGANS  OF  SENSE.  171 

the  nerves  of  some  persons  are  coarser  than  those  of  other  persons,  and 
this  is  one  way  in  which  we  may  account  for  the  difference  of  colors 
which  different  people  experience  when  looking  at  the  same  thing. 

474.  Again,  suppose  the  light  from  any  part,  on  account  of  some 
wrong  state  or  form  of  the  sclerotic,  vitreous  humor,  lens,  aqueous  hu- 
mor, or  cornea,  which  as  before  set  forth  may  exist,  arrives  at  the  retina 
just  before  it  crosses,  as  in  Lith.  PI.  5,  Fig.  3,  then  the  light  from  y,  which 
we  will  consider  yellow,  will  act  on  some  of  the  same  nerves  as  the  light 
from  b,  which  may  be  considered  as  blue,  and  the  light  from  r,  which 
may  be  considered  as  red,  will  act  on  a  part  of  the  same  nerves  as  the 
light  from  y.     In  this  case,  there  must  be  two  causes  of  confusion :    1st. 
The  light  from  y,  which  should  act  on  a  single  nerve,  and  would  thus 
produce  an  intense  effect,  acts  over  several  nerves,  and  produces  but  a 
slight  effect  upon  any  one.     2d.   The  light  from  different  objects  acting 
on  the  same  nerves,  distinct  sensations  cannot  be  caused. 

475.  Again,  suppose  from  some  wrong  state  of  some  part  or  parts 
of  the  eye,  the  light  is  bent  so  as  to  cross  before  it  reaches  the  retina, 
as  in  Lith.  Fig.  4,  Pi.  5.     It  is  seen  that  the  same  results  are  produced, 
the  same  indistinctness  of  vision  as  described  in  the  preceding  paragraph, 
but  the  causes  are  quite  different. 

476.  Where  the  light  reaches  the  retina  before  it  crosses, 
the  eye  is  called  long-sighted. 

In  this  case  it  is  necessary  to  do  something  which  will  cause  the 
light  to  bend  to  a  greater  degree,  and  reach  its  focus  at  the  same  in- 
stant it  reaches  its  nerve.  A  convex  lens  is  required  for  reasons  hereto- 
fore seen.  If  this  be  placed  before  the  eye,  the  light  will  be  bent  before 
it  enters  the  eye,  and  the  contents  of  the  eye  will  do  the  rest,  as  seen  in 
(Fig.  71).  The  convexity  of  the  lens  required,  must  depend  upon  how 
much  the  eye  fails  to  fulfil  its  duty,  for  the  less  the  eye  bends  the  light, 
the  more  must  the  lens  be  called  upon  to  do. 

477.  Where  the  light  crosses  before  it  reaches  the  retina, 
the  eye  is  called  short-sighted. 

In  this  case  a  lens  called  concave  will  be  required,  and  which  oper 
ates  to  bend  the  light  from  the  axis  of  the  lens,  instead  of  towards  it,  as 
in  the  case  of  the  convex  lens.  Thus  the  light  being  bent  out,  if  the 
expression  may  be  used,  as  in  (Fig.  72),  the  eye  will  bend  it  back  again, 
and  in  such  manner  that  it  will  cross  at  the  instant  it  reaches  the  nerve. 
The  degree  of  concavity  of  the  lena  must  depend,  of  course,  upon  th« 


172  ORGANS  OF  SENSATION  OR  FEELING.         [CHAP.  II. 

Fig.  71. 


Fig.  71. — A,  represents  a  lens  causing  the  light  to  bend  before  it  enters  the  eye,  whien 
Is  able  to  bend  the  light  in  the  direction  of  the  dotted  lines,  so  as  to  produce  foci  at  the 
back  part  of  the  eye  instead  of  at  B,  as  represented  by  the  continuous  lines  in  which 
the  light  would  pass  if  there  were  no  lens  in  front  of  the  eye.  The  situation  of  the 
dotted  lines  is  not  correct,  except  in  the  fact  that  the  foci  are  at  the  retina. 

The  light  is  here  represented  as  converging  when  it  falls  upon  the  lens ;  thi-3  is  sel- 
dom the  case.  It  usually  is  diverging  when  it  comes  from  any  object  to  the  eye,  as  in 
Fig.  72.  When  an  object  is  very  far  distant,  the  light  is  generally  considered  as  coming 
in  parallel  rays,  as  represented  by  Fin.  57,  but  it  is  seldom  if  ever  the  case  that  it  is  so. 
If  it  should  be  so,  why  should  the  light  from  different  points  of  an  object  falling  upon 
the  entire  surface  of  the  lens,  be  brought  to  different  foci  ?  That  different  foci  may  be 
formed  by  the  light  coming  from  different  points  of  an  object,  it  is  necessary  that  the 
rays  of  light  from  the  different  points  should  fall  upon  the  lens  with  different  degrees 
of  obliquity,  when,  though  they  may  fall  upon  the  same  point  of  the  lens,  a  different  di- 
rection corresponding  to  the  obliquity  will  be  given  to  them,  and  they  will  produce  foci 
at  different  points. 


degree  of  short-sightedness  of  the  eye.     The  kind  of  glasses  adapted  to 
the  eye  is  ascertained  by  trial. 

478.  Another  matter  may  now  come  before  the  mind.  If  an  ex- 
periment be  tried  with  the  sun-glass  and  candle,  it  will  be  found  that 
the  distance  of  the  focus  from  the  lens  will  vary  with  the  distance  of 
the  candle,  to  wit,  when  the  candle  is  carried  to  a  distance  from  the 
lens,  the  focus  is  nearer  the  lens  than  when  the  light  is  placed  near  the 
lens.  The  reasons  for  this  it  is  not  necessary  to  discuss  ;  the  experiment 
proves  the  fact,  as  represented  by  (Fig.  73).  If  therefore,  a  nerve  were 
at  the  focus  of  a  distant  object,  it  could  not  also  be  at  the  focus  of  a  near 
object  at  the  same  time.  But  objects  which  are  distant,  and  those  which 
are  near,  produce  distinct  sensations  in  the  eye  if  it  be  perfect  in  every 
respect.  Yet  the  apparatus  of  the  eye  which  bends  the  light,  acts  in 
the  same  manner  as .  the  lens  used  with  the  candle,  as  is  seen  in  the 
case  of  long-sighted  and  near-sighted  persons.  For  near-sighted  persons 
bring  an  object  which  they  wish  to  see,  quite  close  to  the  eye,  because 
when  it  is  at  a  distance,  the  light  coming  from  it  crosses  or  forms  its 
focus  before  it  arrives  at  the  norve  ;  but  the  nearer  the  object  is  brought 
to  the  eye,  the  farther  from  the  lens  is  the  focus  formed,  until  it  is  formed 
at  the  nerve,  when  near-sighted  persons  can  see.  In  case  of  long-sight- 
ed persons,  th«  fe«na  would  be  formed  too  far  from  the  lens ;  and  they 


SEC.  3.] 


ORGANS  OF  SENSE. 
Fig.  72. 


173 


pjcr.  72. — B,  C,  concavo-concave  lens.    Light  in  passing  through  it  is  observed  to  b» 
bent  from  the  axis  A,  E,  as  in  case  of  A,  D,  A,  F. 

therefore  remove  an  object  from  the  eye,  till  at  such  a  distance  that  its 
light  will  form  a  focus  at  the  nerve. 


Fig.  73. 


Fig.  73.— A,  A,  a  lens  by  which  the  light  passing  from  o,  is  bent  to  a,  while  if  th« 
object  producing  light  be  moved  to  d,  the  light  coming  from  a  more  distant  point  is 
bent  to  a  nearer  point  on  the  opposite  side,  as  shown  by  the  dotted  lines. 


479.  It  cannot  be,  therefore,  that  the  eye  remains  the  same  when 
looking  at  a  near  object,  in  case  of  one  who  sees  equally  well  objects 
at  a  distance.  How  the  eye  is  altered  is  not  however  known.  There 
are  many  hypotheses.  If 'an  experiment  be  tried  with  the  lens  and 
candle,  such  that  the  object  upon  which  the  focus  falls  remains  perma- 
nent, as  does  the  retina  in  the  eye,  and  while  the  candle  is  removed  from 
the  lens,  the  lens  be  also  removed  towards  the  retina,  if  I  may  call  it  so. 


174  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II* 

the  focus  will  be  seen  to  remain  always  at  the  retina.  When  the  candle 
is  brought  again  towards  the  lens,  the  lens  must  be  removed  from  the 
object.  This,  of  course,  is  the  same  thing  as  if  the  lens  should  be  perma- 
nent, and  the  retina  should  be  caused  to  change  place  with  the  motions 
of  the  candle.  On  account  of  the  results  of  this  experiment,  some  have 
thought  the  apparatus  which  bends  the  light,  is  moved  forward  or  back- 
ward, as  we  look  at  near  or  distant  objects.  Some  have  thought  that 
the  eye  was  made  deeper  by  the  pressure  of  the  muscles  when  we  look  at 
near  objects,  by  which  means  the  bending  or  refracting  apparatus  of  the 
eye  would  be  made  more  distant  from  the  retina.  There  are  many  ob- 
jections "to  this.  The  sclerotic  is  very  unyielding,  and  causes  unpleasant 
feeling  when  pressed  gently.  Some  think  the  lens  of  the  eye  is  drawn 
forward  when  we  look  at  near  objects,  and  moved  back  when  we  look 
at  distant  objects.  But  there  does  not  seem  to  be  any  means  for  accom- 
plishing this  duty,  for  it  must  be  moved  very  much  to  accomplish  the 
desired  end.  Others,  again,  have  suggested  that  the  adaptation  of  the 
eye  was  produced  by  the  increased  and  diminished  density  of  certain 
parts  of  the  eye.  Others  have  thought  a  change  in  the  position  of  the 
lens  in  its  place  would  give  the  desired  result.  Others,  again,  have  said 
that  the  object  was  gained  by  the  change  in  the  size  of  the  pupil,  which 
will  be  noticed  to  diminish  when  near  objects  are  observed.  None  of 
these  three  opinions  can  be  correct,  as  is  quite  evident  without  remark. 
Some  again  have  thought,  that  light  coming  from  an  object  produced  a 
variety  of  foci,  to  wit,  that  passing  through  the  outskirts  of  the  lens  one 
focus,  that  passing  through  the  central  portions  of  the  lens  other  foci. 
This  is  not  so,  as  heretofore  proved  ;  but  if  it  were,  the  conclusion  would 
not  be  correct,  which  is  this,  that  the  light  from  a  near  object  passing 
through  the  outskirts  of  the  lens  produces  a  focus  at  the  nerve,  at  the 
same  time  <that  ''he  light  from  a  distant  object  passing  through  the  centre 
of  the  lens  produces  a  focus  at  the  same  nerve  ;  for  in  this  case  objects 
in  the  same  direction  from  the  eye  would  have  their  foci  upon  the  same 
nerve  at  the  same  time,  and  could  not  be  distinguished.  No  theory  yet 
suggested  is  valid. 

480.  There  is,  however,  no  doubt  of  the  fact,  that  the  eye  possesses 
the  power  of  adaptation,  for  people  have  it  and  lose  it,  as  in  case  of  those 
who  become  near-sighted,  or  long-sighted.  This  last  is  many  times 
produced  from  not  exerting  the  power.  The  sailor  who  is  in  the  habit 
of  using  his  eyes  to  look  at  distant  objects,  loses  to  a  degree  the  power 
of  examining  near  objects ;  while  the  student  who  occupies  the  most  of  his 


SEC.  3.]  ORGANS  OF  SENSE.  175 

time  in  reading,  loses  the  power  of  seeing  distinctly  distant  objects. 
This  loss  is  to  be  prevented  by  seasonable  and  frequent  attempts  to 
look  at  distant  objects  ;  a  persevering  course  of  the  same  kind  will  enable 
a  person  to  recover  the  power  in  many  instances,  though  it  has  been 
lost  for  years.  Except  by  sailors,  it  seldom  happens  that  the  power  of 
seeing  objects  near  at  hand  is  lost  until  advanced  age.  The  cause  for 
its  loss  then,  is  not  satisfactorily  determined.  It  has  been  by  many  sup- 
posed to  be  owing  to  a  flattening  of  the  cornea,  but  there  is  a  strong  ob- 
jection to  this.  True,  the  cornea  is  flattened  in  old  people,  but  it  is 
much  fuller,  as  a  usual  thing,  in  children  than  in  middle  age  ;  yet  more 
raiddle-aged  people  than  children  are  near-sighted  ;  the  power  possessed 
at  birth,  being  lost  for  want  of  exercise.  How  in  extreme  old  age  the 
power  of  seeing  with  the  acuteness  of  youth  is  sometimes  regained,  can- 
not, with  present  knowledge,  be  explained. 

481.  The  eye  serves  another  very  important  purpose. 
By  means  of  the  eye  we  know  the  direction  of  an  object 
from  us. 

To  explain  how  this  is  done  many  theories  have  been  advanced.  I 
shall  adopt  that  advanced  by  Volkman,  for  I  cannot  perceive  any  objec- 
tion to  it,  though  I  have  looked  upon  it  with  much  caution,  as  Muller 
thinks  it  cannot  be  sustained. 

If  the  reader  will  turn  to  Fig.  59,  he  will  see,  that  the  central  lines  drawn 
from  A  to  d,  and  from  B  to  a,  pass  through  the  same  point  at  o.  If  there 
were  a  hundred  objects  with  their  light  falling  upon  different  points  of  the 
retina,  a  line  drawn  from  the  objects  to  the  point  acted  upon,  would  pass 
through  this  point  o.  This  may  be  called,  therefore,  the  stationary  point, 
fci-  though  the  object  and  the  point  of  the  retina  acted  on  may  charge, 
that  point  (o)  remains  the  same.  The  precise  position  of  this  point  de- 
pends upon  the  form  of  the  lens.  In  case  of  the  eye,  it  has  been  found 
by  very  accurate  measurements,  to  be  just  back  of  the  crystalline  lens. 

482.  There  is  therefore  always  a  point  at  which  all  the 
straight  lines,  drawn  from  objects  to  their  foci,  will  cross. 

483.  If,  therefore,  a  line  be  drawn  from  the  focus  through 
this  point  and  extended,  it  will  reach  the  object  from  which 
the  light  causing  the  focus  has  come. 

484.  Volkman  therefore  believes,  and  I  think  he  is  right, 
that  we  are  so  made  or  constituted,  as  to  believe  that  an  ob- 


176  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

ject  which  causes  light  to  act  on  a  part  of  the  retina,  is  in  a 
straight  line  extended  from  that  point  through  the  stationary 
point. 

In  the  same  manner,  when  we  feel  a  sensation  which  has  been  pro- 
duced through  any  nerve,  we  believe  the  object  producing  the  sensation 
acts  on  the  part  where  ^hat  nerve  commences. 

485.  Another  question  is,  How  do  we  know  the  distances  from  us 
of  different  objects,  and  the  distance  of  these  from  each  other  1  These 
questions  have  been  answered  in  various  ways. 

486.  In  the  first  place,  we  learn  by  experience  the  dis- 
tance of  ohjects. 

For  instance,  we  learn  that  an  object  is  twenty  steps  distant,  by  the 
fact  that  it  requires  the  contraction  and  relaxation  of  certain  musclea 
twenty  times.  This  we  know  by  sensation,  as  heretofore  shown.  If  it 
require  forty  contractions,  &c.,  of  the  muscles,  to  reach  an  object,  we 
consider  that  it  is  twice  as  far  distant  as  the  first.  Now  when  we  look 
at  the  first  object,  a  certain  adaptation  of  the  eye  is  necessary,  that  it 
may  be  seen  distinctly ;  producing  this  adaptation  produces  a  certain 
sensation.  When  we  look  at  the  second  object,  another  adaptation  of 
the  eye  is  necessary,  and  this  produces  another  sensation.  Remembering 
these  sensations,  we  shall  think,  when  these  are  produced  again,  that  the 
objects  are  at  the  same  proportionate  distance  as  before.  Much  experience, 
and  often  produced  sensations,  make  us  remember  them,  and  we  are 
therefore  able  to  form  good  judgments  of  the  distance  of  objects.  A 
near  object  acts  on  a  greater  number  of  nerves  than  the  same  object  at  a 
distance.  Thus  we  judge  of  the  size  of  objects,  first,  by  judging  of  their 
distance,  and  then  of  the  number  of  nerves  upon  which  they  act.  Such 
is  my  belief. 

487.  Thus,  if  all  the  nerves  throughout  the  body  were  alike,  the  eye 
would  be  necessary,  that  we  may  know  the  direction  of  objects  from  us, 
and  the  distanc,-  and  size  of  objects,  when  not  in  contact  with  us.  Nei- 
ther can  the  color  of  objects,  by  which  they  are  distinguished  from  each 
other  while  at  a  distance,  be  known,  without  the  eye.  To  see,  therefore, 
the  eye  is  necessary. 

It  has  been  made  a  source  of  exceedingly  pleasurable  sensations. 
These  are  usually  produced  by  the  combined  action  of  certain  colors. 
Hence  it  is  very  important,  in  selecting  the  colors  of  a  dress,  that  the 
colors  be  such,  that  if  they  act  at  the  same  time  upon  the  same  nerve, 
and  produce  compound  sensations,  these  may  be  agreeable. 


SEC.  3.]  ORGANS  OF  SENSE.  177 

488.  There  are  in  this  connection  two  things  worthy  of  particular 
notice.     Certain  objects  transmit  only  certain  kinds  of  light,  and  when 
these  are  reflected  to  the  eye,  mingled  with  other  light,  they  produce  a 
very  unpleasant  effect,  while  other  objects  transmit  those  kinds  of  light 
that,  reflected  from  various  objects,  produce  pleasant  sensations,  and 
render  the  objects  attractive.     I  shall  be  understood  by  an  illustration. 
Green  paper  curtains  transmit  mostly  green   light,  or   more    properly 
speaking,  yellow  and  blue.     If  this  green  light  be  reflected  from  a  lady's 
cheek,  it   produces  a  very  unpleasant  effect.      The  person  will  look 
ghastly  and  unwell. 

489.  In  the  next  place,  the  light  reflected  from  objects  a  lady  wears 
as  dress,  will  be  more  or  less  mingled  with  the  light  from  the  com- 
plexion, and  thus  compound  sensations  will  be  produced,  which  will  be 
pleasant  or  not,  according  to  the  dress.     An  example  will  illustrate.     If 
a  lady  wear  pea-green  trimming,  it  reflects  green  light  of  course,  and 
some  of  it  being  reflected  to  the  cheek,  will  be  reflected  from  the  cheek 
with  other  light  to  the  eye  of  another  person,  and  an  unpleasant  effect 
will  many  times  be  produced. 

490.  These  principles  are  also  to  be  kept  in  mind,  viz.,  that  colors 
are  judged  by  comparison  ;  and  still  more  important,  that  when  sensa- 
tions of  any  strong  kind  are  produced  for  any  length  of  time,  an  unpleas- 
ant sensation  is  the  result,  however  pleasing  at  first.     Thus  we  become 
tired  of  "  decided  colors."     It  is  in  better  taste,  therefore,  to  dress  in 
svibdued  colors.      In  regard  to  the  point  first  mentioned,  however,  it  is 
to  be  kept  in  rnind  that  it  is  not  the  comparative  color  of  an  object,  but 
the  positive  sensation  it  produces,  which  gives  the  pleasure.     Thus  a 
lady  may  wear  a  bit  of  court-plaster,  that  her  complexion  may  appear 
white  by  contrast,  but  the  positive  sensation  her  complexion  produces 
does  not  depend  at.  all,  or  at  most  but  very  little,  on   the  court-plaster. 
That  affects  merely  what  is  said  of  her,  not  the  sensation  she  can  pro- 
duce.    Nature  has  never  intended  man  or  woman  should  pass  for  any 
thing  other  than  what  he  or  she  is. 

491.  If  it  be  asked  how  these  principles  can  be  made  use  of,  the 
answer  is,  that  a  person   must  learn  what  compound   sensations  are 
agreeable,  and  surround  herself  with  such  articles  of  dress  and  furniture 
as  will  be  pleasing  by  the  effects  they  will  produce  ;  for  we  always  love 
those  in  whose  society  we  find  agreeable  sensations  produced,  of  sight 
or  sound,  or  any  other  sense. 

492.  Jt  will  be  proper  in  conclusion,  to  speak  briefly  of  images,  opti- 
cal instruments — such  as  telescopes,  microscopes,  &c.    All  mention  of 

8* 


178  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

them  has  been  purposely  avoided,  because  much  confusion  is  produced 
in  the  mind  by  the  introduction  of  the  indefinite  term  images,  in  lan- 
guage generally  used  where  these  subjects  are  treated  upon,  and  so  far 
as  I  can  judge,  the  mind  of  the  learner  finds  it  difficult  to  conceive  of 
an  image  of  a  dart  in  the  eye  when  one  is  represented  there  in  a  draw- 
ing. There  is  nothing  like  the  dart  in  the  eye.  The  dart  is  that  wh'ch 
acts  upon  the  light,  while  the  image  is  the  light  itself.  To  illustrate.  If 
light  be  coming  from  a  thousand  different  points  of  an  object,  it  will 
arrive  in  the  eye  at  a  thousand  different  points  or  foci.  These  bear  the 
same  relative  distance  from  each  other  as  the  points  of  the  object  f.om 
which  the  light  has  come,  as  seen  in  Lith  PI  5,  Fig.  2.  That  is,  if  it 
be  as  great  a  distance  from  the  first  point  of  an  object  to  the  second,  as 
it  is  from  the  second  to  the  third,  it  will  be  as  far  from  the  focus  of  the 
first  point  to  the  focus  of  the  second,  as  it  is  from  the  focus  of  the  second 
point  to  the  focus  of  the  third  point.  The  distance  between  the  poiita 
of  the  object  may  be  twelve  inches,  and  the  distance  between  the  foci 
but  half  of  an  inch ;  it  matters  not,  if  the  ratio  of  the  distance  between 
the  foci  be  similar  to  the  ratio  of  the  distance  between  the  points  from 
whence  come  the  foci  causing  light.  These  foci  are  called  images  of 
the  points  of  an  object  from  which  the  light  has  come,  and  the  foci 
formed  by  light  from  all  the  points  of  an  object  are  called  the  image  of 
the  object.  Again,  when  light  passes  from  an  object  to  a  mirror,  it  will 
be  reflected  entire.  That  is  to  say,  whatever  kind  of  light  passed  to 
the  mirror,  will  be  reflected  from  it,  for  the  mirror  does  not  change  the 
nature  of  the  light,  but  only  the  direction.  If  the  mirror  have  a  "  true  " 
surface,  the  light,  as  in  Fig.  74,  will  be  in  the  same  relations  after  being 
reflected  as  before.  It  will,  of  course,  make  no  difference  how  many 
times  a  single  particle  of  red  light,  for  instance,  is  bent  in  its  course  to 
the  eye ;  acting  by  itself,  it  can  produce  but  one  effect  on  the  eye,  under 
any  circumstances,  and  that  will  be  the  sensation  of  red.  Its  being  bent 
only  affects  our  belief  of  the  direction  whence  it  comes,  which  is,  that  it 
has  come  in  a  straight  line,  drawn  from  the  point  of  the  nerve,  where 
the  impression  was  produced  through  the  "  stationary  "  point ;  so,  also, 
if  the  light  of  many  different  kinds,  from  many  different  points,  produce 
many  different  foci,  it  will  make  no  difference  if  all  the  light  be  bent, 
provided  the  light  from  all  the  objects  be  bent  at  the  same  time  and  in 
the  same  manner,  by  which  the  same  relative  distances  will  exist  between 
the  foci  as  existed  between  the  objects  from  which  the  light  came  An 
image  is  said  to  be  produced  at  the  mirror,  but  there  is  no  more  an 
image  there  than  at  any  other  point  between  the  object  and  mirror,  or 


SEC.  3.]  ORGANS  OP  SENSE.  179 

between  the  mirror  and  eye.  For  at  any  such  point,  the  light  exists  in 
the  same  relations  as  when  it  left  the  object.  And  wherever  the  light 
from  an  object  exists  in  the  same  relations  as  when  it  left  the  object,  there 
is  an  image  in  an  optical  sense.  It  is  not  known  to  be  there,  till  the 
eye  be  placed  there,  or  an  object  which  shall  reflect  the  light  to  the  eye 
without  altering  its  relations,  any  more  than  the  place  of  the  focus  of  the 
light  from  a  candle,  passing  through  a  sun-glass,  is  known  till  the  eye 
be  placed  where  it  is,  or  an  object  be  so  placed  as  to  bend  the  light  to 
the  eye  ;  for  the  eye  must  either  go  to  the  focus  or  the  focus  must  be 
brought  to  the  eye  that  it  may  produce  a  sensation,  without  which  its 
existence  is  unknown.  But  it  will  be  said,  perhaps,  that  the  image 
appears  to  exist  behind  the  mirror.  Very  well.  It  is  readily  seen  that 
the  light  reflected  from  the  mirror  should  appear  to  be  produced  in  that 
direction,  for  it  is  so  with  all  reflecting  objects  in  nature.  They  reflect 
the  light  of  the  sun,  for  instance,  yet  the  mind  thinks  nothing  about  the 
sun,  and  till  taught,  knows  nothing  where  the  light  was  produced,  but 
believes  it  came  from,  and  was  produced,  by  the  object  that  last  reflected 
it.  It  may  have  been  reflected  a  thousand  times  before,  or  not  once ; 
the  mind  is  not  influenced  thereby. 

Fig.  74. 


Fig.  74.  —Represents  light  passing  from  the  points  A,  B,  to  the  mirror  w,  from  which 
it  is  reflected  or  turned  backward  more  or  less,  according  as  it  strikes  perpendicularly 
upon  the  mirror  or  in  a  slanting  direction. 

493.  In  the  next  place  I  have  endeavored  to  show,  that  from  experi- 
ence the  mind  learns,  or  is  constituted  so  as  to  believe,  that  when  on* 
adaptation  of  the  eye  produces  a  sensation,  the  object  seen  is  distant ; 


180  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

and  when  another  adaptation  of  the  eye  produces  another  sensation,  the 
object  is  near.  I  have  endeavored  to  show,  that  the  reason  why  an 
adaptation  of  the  eye  was  necessary,  was,  because  the  light  from  a  dis- 
tant object  falls  less  obliquely,  or  slanting,  upon  the  cornea,  as  seen  in 
Fig.  73,  than  the  light  from  a  near  object ;  hence,  though  in  fact  bent 
less  than  the  light  from  a  near  object,  it  is  not  necessary  it  should  be,  and 
yet  it  will  be  brought  to  a  focus,  nearer  to  the  lens  than  the  light  from  a 
near  object.  Hence  the  adaptation  of  the  eye  will  be  required,  not  abso- 
lutely according  to  the  distance  of  the  object,  but  according  to  whether 
the  light  fall  perpendicularly,  or  obliquely,  on  the  surface  of  the  cornea. 
If  the  object  be  near,  and  the  light  by  glasses  can  be  made  to  fall  quite 
perpendicularly  upon  the  cornea,  the  same  adaptation  of  the  eye  will  be 
required  to  cause  the  light  to  bend  to  a  focus  at  the  nerve,  as  if  the  light 
came  perpendicularly  upon  the  cornea  from  a  distant  object.  It  is  seen 
by  Fig.  74,  that  light  coming  from  any  point  of  an  object  after  being  re- 
flected, passes  in  the  same  manner  as  before,  viz.,  in  a  diverging  man- 
ner ;  and  of  course,  when  it  falls  upon  the  eye,  has  the  same  obliquity  to 
the  surface  of  the  eye,  as  if  it  had  passed  through  the  same  distance 
without  being  reflected  ;  and  of  course,  the  same  adaptation  of  the  eye 
is  required,  that  the  focus  may  be  at  the  nerve.  Consequently,  the  light 
seems  to  come,  as  it  does,  from  the  direction  of  the  mirror ;  but  from  a 
much  greater  distance,  and  hence  seems  to  be  behind  the  mirror.  An 
image  then — in  an  optical  sense — is  not  a  picture,  not  a  representation, 
not  an  outline,  but  is  an  arrangement  of  light  which  has  come  from 
an  object ;  not  the  object,  nor  the  shadow  of  an  object,  nor  the  painting 
of  an  object :  all  these  things  will  cause  light  to  produce  the  same  effecta 
as  an  image  would ;  indeed,  will  cause  light  to  become  an  image — 
optically  speaking. 

494.  It  is  desirable  many  times  to  obtain  more  light  from  any  given 
object  than  will  fall  upon  the  cornea,  and  enter  the  pupil.  In  a  dark 
room,  there  may  be  light  enough  coming  from  the  objects  to  produce  on 
the' nerves  slight  sensations,  but  so  slight,  the  objects  cannot  be  seen 
distinctly.  Two  ways  may  now  be  taken,  to  make  the  object  more  dis- 
tinct ;  either  admit  light  to  the  room,  or  gather  more  of  the  light  coming 
from  an  object,  and  cause  it  to  enter  the  pupil.  This  last  can  be  done 
by  means  of  a  large  lens,  as  seen  in  Fig.  57.  Without  this,  the  light  is  so 
feeble  that  only  six  rays  of  light,  for  example,  can  enter  an  opening  the 
size  of  the  pupil ;  but  one  hundred  rays  fall  upon  a  large  lens,  which  will 
so  bend  them  that  all  the  hundred  can  enter  the  pupil,  and  act  on  the 
end  of  the  same  nerve,  as  seen  in  Fig.  57,  that  six  only  acted  uppn 


SEC.  3.]  ORGANS  OF  SENSE.  181 

before — the  sensation  becomes  much  more  intense  of  course.  This  is 
the  grand  principle  upon  which  a  telescope  or  microscope  is  constructed. 
It  will  be  seen,  however,  that  another  glass  or  lens  is  required  ;  as  the 
light  which  has  passed  through  the  large  lens,  called  an  object-glass,  is 
so  bent  that  if  it  fall  on  the  cornea  before  it  reach  the  focus,  it  will  be 
too  perpendicular  to  the  surface  of  the  cornea,  as  seen  in  Fig.  57,  sup- 
posing the  cornea  should  be  placed  at  2.  If  the  light,  after  it  has  passed 
the  focus,  fall  on  the  cornea,  it  will  be  too  oblique  to  be  bent  by  the  eye 
in  such  a  manner  that  its  focus  may  be  at  the  retina.  Such  evils  are 
corrected  by  a  convex -glass,  placed  beyond  the  focus ;  the  light  in  passing 
through  this  is  bent  to  a  degree,  and  the  eye  can  accomplish  the  rest 
(Fig.  75).  Other  glasses  are  added,  to  obtain  minor  benefits,  the  nature 
of  which  may  be  better  learned  elsewhere.  In  case  of  a  microscope 
and  magnifying- glass,  much  the  same  principles  operate. 

It  is  desirable  to  have  a  great  deal  of  light  from  a  small  object  enter 
the  pupil.  If  an  object  be  held  very  near  a  lens,  a  great  deal  of  light 
from  a  few  points  will  fall  upon  it,  and  fall  very  obliquely — hence  it  will 
be  very  much  bent ;  but  if  the  distance  of  the  object  be  right,  not  so  much 
as  to  pass  to  a  focus,  but  to  go  to  the  eye  in  parallel  lines — as  in  Fig.  57. 
Suppose  m  to  be  the  object,  and  the  light  to  pass  from  it  through  the  lens. 
If  the  object  be  too  far  from  the  lens,  the  light  will  be  bent  so  as  to 
cross  ;  if  the  object  be  too  near  the  lens,  the  light  will  not  be  bent 
enough  to  form  parallel  rays — and  in  either  case  the  eye  could  not  cause 
the  light  passing  from  the  lens  into  it,  to  form  a  focus  at  the  retina. 
The  distance  of  the  object  from  the  lens,  will  of  course  depend  upon  the 
convexity  of  the  lens.  In  this  case,  represented  by  Fig.  58,  some  of  the 
light  falling  upon  the  lens,  does  not  enter  the  eye.  But  if  the  lens  be 
very  convex  and  the  object  brought  very  near  the  lens,  a  great  deal 
of  the  light  passing  from  any  point  of  an  object,  must  fall  upon  the  lens, 
in  the  first  place  ;  and  by  the  convexity  of  the  lens,  it  will  be  so  bent  as 
to  produce  a  focus.  In  this  case,  however,  there  must  be  another  glass 
between  the  object-lens  and  the  eye,  for  the  same  reason  there  must  be 
in  case  of  the  telescope,  viz.,  to  bend  the  light  in  such  a  way,  that  in 
passing  through  the  eye,  the  bending  powers  of  the  eye  may  bring  the  focus 
upon  the  retina.  By  the  application  of  principles,  previously  laid  down, 
it  is  easily  seen  why  an  object  viewed  through  a  telescope,  should  appear 
BO  near  ;  and  why  an  object  seen  through  a  microscope,  should  appear  so 
large.  Reflecting  telescopes,  camera  obscuras,  and  the  like,  are  made 
with  only  a  variation  of  the  application  of  the  principles  mentioned. 
The  grand  principle  being,  to  cause  the  light  from  an  object  to  bend  in 


182  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  IT. 

Buch  a  manner  that  a  large  amount  of  light  may  so  fall  upon  the  cornea, 
that- the  refracting  apparatus  of  the  eye  may  cause  it  to  act  on  a  single 
nerve  and  produce  a  distinct  impression,  which  will  cause  a  distinct  sen- 
eation. 

Fig.  75. 


F.   The  Sense  of  Hearing. 

495.  The  ear  is  the  organ  of  this  sense.     By  means  of 
the  ear,  distant  objects  cause  sensations. 

For  if  the  ear  be  perfectly  closed,  sound  is  not  caused  by  surrounding 
objects.  By  experiment  it  has  been  found,  that  if  a  bell  be  shaken  in  a 
glass  from  which  the  air  has  been  removed,  sound  is  not  caused  by  the 
bell,  but  the  instant  the  air  is  admitted  the  usual  ringing  is  heard.  It 
follows  therefore,  that, 

496.  Surrounding  objects  act  upon  the  air,  and  cause  the 
air  to  produce  effects  upon  the  ear. 

These  effects  are  called  impressions,  and  acting  through  the  nerve  of 
hearing  and  the  brain,  they  cause  sensations. 

497.  Four  things  are  necessary  that  sound  may  be  pro- 
duced.    1.  An  object  to  act  upon  the  air.     2.  The  air  to  be 
acted  on  by  the  object,  and  then  to  act  on  the  ear.     3.  The 
ear,  including  all  its  connectives  of  nerve,  brain,  &c.  4.  The 
mind. 

498.  The  sensation  produced  or  the  quality  of  sound  will  depend, 
therefore,  on  the  nature  of  the  object,  the  character  of  the  air,  the  nature 
and  condition  of  the  ear  and  its  connectives,  and  the  mind. 

499.  So  far  as  we  can  learn,  the  nature  of  objects  is  always  the  same 
under  similar  circumstances.     It  is  exceedingly  different  in  case  of  dif- 
ferent objects,  or  the  same  objects  under  dissimilar  circumstances.     Al- 


SEC.  3.]  ORGANS  OF  SENSE.  183 

most  every  object  in  nature  has  a  voice,  distinguishing  it  from  every 
other  object,  even  of  its  own  kind,  in  every  other  respect.  There  are 
millions  of  the  human  family,  more  numerous  still  are  the  beasts  of  the 
field  and  of  the  forest,  besides  almost  innumerable  birds  and  a  tenfold 
number  of  insects  ;  but  the  blind  man  distinguishes  the  voice  he  has  ever 
heard  ;  each  sheep  knows  the  bleating  of  her  own  lamb,  and  every  bird 
the  call  of  its  own  mate.  It  would  be  as  difficult  to  find  two  objects 
producing  precisely  similar  sounds,  as  for  the  child  to  find  two  similar 
blades  of  ribbon-grass,  which  every  one  has  probably  tried  in  vain. 

If  the  hand  be  placed  upon  a  ringing  bell,  a  jarring  feeling  will  be  pro- 
duced. This  is  owing  to  the  motions  of  the  particles  of  the  bell,  for  though 
it  seems  so  solid  and  thick,  its  substance  is  thrown  into  very  rapid  but 
not  very  extensive  motions.  If  a  tuning-fork  be  struck  and  brought  near 
the  eye,  its  rapid  motions  will  be  perceived.  If  the  eye  be  directed  to 
the  strings  of  the  piano  or  violin  when  played,  or  if  the  hand  be  laid  upon 
them,  their  rapid  motions  will  be  at  once  perceived.  If  a  tumbler  be 
struck,  a  similar  effect  will  be  produced. 

500.  Vibrations  is  the  name  given  to  the  motions  of  ob- 
jects when  they  are  acting  to  produce  sound. 

501.  If  a  tumbler  containing  water  be  struck,  the  water  will  be 
thrown  into  waves  by  the  action  of  the  vibrations  of  the  tumbler  upon  it. 
If  air  instead  of  water  were  in  the  tumbler,  the  vibrations  of  the  tumbler 
would  throw  the  air  into  waves  similar  to  the  waves  of  the  water.  In 
the  same  manner  the  strings  of  the  violin,  the  guitar,  the  piano,  the  head 
of  a  drum,  &c.,  produce  waves  in  the  air  in  contact  with  them.  When  a 
cannon  is  fired,  a  heavy  bell  rung,  or  the  deep  tones  of  an  organ  played, 
the  waves  are  so  powerful  as  to  jar  the  body  in  a  very  perceptible  man- 
ner, to  rattle  the  windows,  or  in  case  of  the  cannon,  to  break  the  glass. 
If  the  fingers  be  brought  near  the  lips  of  a  person  while  speaking,  the 
waves  produced  by  the  voice  will  be  noticed ;  hence, 

502.  All  sound -producing  objects,  by  vibrating,  act  upon 
the  air  and  throw  it  into  waves. 

503.  The  peculiar  character  of  the  waves  will  depend 
upon  the  vibrations  producing  them,  and  the  state  of  the  air 
in  which  they  are  produced. 

504.  If  a  stone  be  dropped  into  water,  waves  will  be  noticed  to  flow 
out  in  a  circular  direction  from  the  point  acted  upon.     It  will  also  be  ob- 
served, that  the  waves  grow  smaller  the  greater  the  distance  from  where 


184  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

they  commenced,  until  at  a  certain  distance  the  water  is  undisturbed. 
If  the  water  be  calm  the  waves  will  flow  in  a  circular  manner,  but  if 
the  water  be  running  in  any  direction,  the  waves  will  extend  to  a  greater 
distance  in  that  direction,  and  the  waves  instead  of  being  circular,  will 
be  more  or  less  oblong.  It  is  the  same  with  the  air,  except  that  the 
waves  of  air  are  spherical ;  they  pass  off  in  all  directions,  growing  less 
and  less,  and  extending  farthest  in  any  direction  with  a  current  of  air  than 
against  it ;  thus, 

505.  The  air-waves  produced  by  the  vibrations  of  sound- 
producing   objects,   act  through   the   ear   upon  nerves   and 
cause  impressions. 

The  nearer  the  object  producing  the  sound,  all  other  things  being  simi- 
lar, the  more  powerful  the  impression.  If  the  wind  be  blowing  towards 
the  ear  from  the  sound-producing  object,  a  more  powerful  impression  is 
produced  than  if  the  wind  be  blowing  from  the  ear  towards  the  object ; 
hence, 

506.  The  more  powerful  the  wave  of  air,  all  other  things 
being  equal,  the  more  powerful  the  impression. 

507.  We  learn  also,  that,  other  things  being  similar,  the 
more  powerful   the  impression,  the  nearer  is  the  object  pro- 
ducing it. 

508.  If  a  stone  be  dropped  in  the  water  near  the  perpendicular  face 
of  a  rock  or  aught  else  in  the  water,  the  waves  will  be  seen  to  strike 
against  the  rock,  and  then  be  apparently  sent  back,  or  reflected,  as  the 
expression  is  ;  and  as  they  go  backward  they  grow  smaller  and  smaller,  to 
the  same  degree  precisely  as  if  the  rock  had  not  been  there,  and  the  waves 
had  gone  on  in  a  straight  line ;  that  is  to  say,  if  the  stone  were  dropped 
into  the  water  three  feet  from  the  rock,  and  caused  waves  to  strike 
against  the  rock  and  flow  back,  when  they  had  gone  back  one  foot  from 
the  rock,  they  w  >uld  be  of  the  same  size  as  those  waves  which  had  gone 
in  another  direction,  and  found  nothing  to  obstruct  them  when  they  were 
four  feet  from  where  they  were  produced.  Thus  it  is  with  waves  of  the 
air ;  if  a  person  fire  a  pistol,  the  waves  it  produces  striking  against  a 
steep  hill,  bank,  ledge,  house,  or  the  like,  will  be  sent  back  ;  by  the  time 
they  reach  the  person's  ear,  however,  they  will  be  very  small,  and  pro- 
duce but  a  slight  effect  or  impression.  As  this  is  feeble,  the  cause  of  it, 
viz.,  the  pistol,  will  appear  to  be  a  long  distance  off.  This  is  what  is 
called  an  echo.  It  seems  to  a  person  as  if  a  pistol  were  fired  a  Icng  djs- 


SEC.  3.]  ORGANS  OF  SENSE.  185 

tance  off,  and  in  a  certain  direction,  viz.,  in  that  direction  from  which 
the  waves  come  to  the  ear. 

509.  We  judge  any  sound-producing  object  is  in  the  direc- 
tion from  which  the  waves  of  air  it  produced  came  to  our  ears. 

510.  The  states  of  the  air  affecting  the  character  of  its 
waves,  depend  upon  its  temperature,  its  degree  of  moisture, 
and  its  density. 

Upon  these  it  will  not  be"worth  while  here  to  speak,  farther  than  to 
say,  these  different  states  of  the  atmosphere  modify  considerably  the  ef- 
fects which  vibrating  objects  produce  upon  it,  and  of  course  modify  the 
effects  it  produces  upon  the  ear.  Before  passing  to  consider  this  organ, 
I  cannot  forbear  expressing  the  astonishment  that  almost  confounds  me, 
when  I  think  of  the  innumerable  variety  of  waves  which  may  be  pro- 
duced in  the  air — the  simple  air.  It  sometimes  seems  as  if  it  could  not 
be  so. 

511.  The  ear  is  a  complicate  piece  of  apparatus  or  me- 
chanism, for  the  purpose  of  causing  the  air-waves  to  act  in  a 
proper  manner  upon  the  commencing  points  of  the  nerves 
of  hearing. 

512.  The  external  ear  is  so  well  known  as  not  to  need  description  or 
remark,  except  that  it  is  uncertain  whether  it  is  of  much  assistance  in 
hearing  or  not.  Some  persons,  who  have  lost  it  by  accident  or  disease, 
have  not  felt  its  loss.  By  o.thers,  it  is  thought  of  much  importance. 

513.  From  the  external  ear,  a  tube  leads  into  the  head, 
from  half  an  inch  to  an  inch  and  a  quarter,  when  it  is  closed 
by  what  is  called  the  membrane  of  the  tympanum  (drum), 
or  sometimes,  the  outer  drum-head. 

514.  This  tube  is  protected  by  hairs  found  at  i*<3  commencement,  and 
by  what  is  called  ear-wax.  This  is  found  in  follicles  or  cryptse,  viz.,  little 
pouches  with  openings  upon  the  surface  of  the  tube.  They  are  similar 
to  those  forming  the  oil  upon  the  skin,  and  the  mucus  of  the  mucous 
membranes.  It  is  sometimes  formed  very  rapidly,  collects  in  the  ear- 
tube,  hardens,  and  causes  a  greater  or  less  degree  of  deafness.  When 
deafness  is  produced  by  this  cause,  it  can  be  removed  by  dropping  into 
the  ear  a  few  drops  of  sweet  oil,  and  retaining  it  a  short  time  with  a  bit 
tf  cotton,  chewed  paper,  or  the  like,  when  the  oil  and  any  collections 


186  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

in  the  ear  are  to  be  removed  by  a  thorough  syringing  with  castile  soap 
and  warm  water.  It  is  said  that  many  cases  of  deafness  are  thus  cured, 
and  many  others  very  much  relieved.  It  is  here  seen  how  much  people 
are  imposed  upon,  who  are  induced  to  buy  at  great  expense  a  small  bot- 
tle of  ear-oil,  which  cannot  be  better  than  sweet  oil  and  probably  is  not 
as  good,  while  the  chief  good  is  all  the  while  to  be  derived  from  the 
syringing  with  soap  and  water,  viz.,  from  cleanliness. 

515.  The  membrane  which  closes  the  end  of  this  tube, 
passes  downward  and  inward  slightly,  as  seen  in  Fig.  76.    Its 
utility  depends  upon  its  flexibility.  It  is  necessary  it  should  be 
acted  on  by  the  slightest  wave  of  air  which  comes  down  the 
tube. 

516.  Passing  through  the  membrane  of  the  tympanum 
(drum),  we  arrive  in  the  tympanum  (B,  Fig.  76.)     This  is 
about  the  form  and  size  of  a  kidney  bean  ;    it  is  filled  with 
air.      Opposite  the  outer  drum-head  are  what  are  called  the 
inner  drum-heads,  viz.,  two  openings  (2,  3)  closed  with  mem. 
branes ;  one  is  of  an  oval  form,  and  called  the  foramen  ovale 
(oval  hole) ;  the  other  is  called  the  foramen  rotunda  (round 
hole).     They  will  again  be  noticed.     At  the  back  part  open, 
ings  are  found,  leading  into  what  are  called  the  mastoid  cells, 
viz.,  cells  in  the  mastoid  bone,  which  is  found  and  may  be 
felt  just  back  of  the  ear.     The  use  oFthe  cells  is  not  known. 
They  are  supposed  in  some  way  to  facilitate  the  power  of 
hearing.     At  the  lower  part,  the  drum  of  the  ear  terminates 
in  a  small  tube,  called  the  Eustachian  tube,  which  leads 
down  /nto  the  back  and  lower  part  of  the  nose,  or  into  the 
upper  and  back  part  of  the  throat.      Through  this  the  air 
has  a  free  passage  to  and  from  the  ear,  and  any  substance 
can  pass  this  way  from  the  ear-drum. 

517.  The   lining   of  the  nose  extends  up  through   the 
Eustachian  tube,   and   lines  the  drum  of  the  ear,  and  of 
course  the  drum-heads,  and  also  lines  the  mastoid  cells. 

518.  Any  disease,  therefore,  affecting  the  throat    or  lining  of  the 
nasal  cavity,  would  easily  extend  to  the  Eustachian  tube,  and  through 


SEC.  3.] 


ORGANS  OF  SENSE. 
Fig.  76. 


187 


Fig.  76.— Is  an  ideal  representation  of  some  of  the  principal  parts  of  the  ear.  The 
dark  dotted  part  corresponds  to  the  bone.  A,  represents  the  tube  leading  inward  from 
the  external  ear.  The  skin  which  covers  the  ear  is  seen  lining  the  passage,  the  mem- 
brane at  the  bottom  of  the  ear-tube,  and  also  the  pouches,  sacs,  or  cryptae,  on  either 
side.  The  sacs  are  not,  however,  in  the  bone  as  here  shown,  on  account  of  being  so 
much  magnified.  The  sacs  are  thousands  in  number,  and  form  the  ear-wax.  B,  rep- 
resents, but  not  in  form  or  size,  the  drum  of  the  ear.  At  the  lower  part  a  tube,  repre- 
senting the  Eustachian,  is  seen  leading  into  the  nose,  and  lined  with  a  continuation  of 
the  lining  of  the  nose,  a,  6,  c,  d,  The  four  bones  connected  upon  one  side  with  the  ex- 
ternal membrane,  and  on  the  other  side  to  the  membrane  (2)  leading  into  the  labyrinth. 
y,  is  a  muscle,  the  use  of  which  is  not  well  determined.  C,  may  be  taken  to  repre- 
sent the  labyrinth  rilled  with  fluid  and  containing  the  sac  D,  which  is  also  filled  with  fluid. 
The  nerve  of  hearing  is  seen  coming  through  the  wall  of  bone  surrounding  the  laby- 
rinth, and  dividing  and  subdividing  with  its  points  towards  the  inner  surlace  of  the 
uac,  as  seen  at  the  extremities  of  the  lines  with  which  i  is  connected. 


188  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

that  to  the  lining  of  the  ear-drum  and  produce  derangement  of  the  hear- 
ing apparatus,  and  hardness  of  hearing.  Hence  why  colds,  catarrhs, 
scarlet  fever,  attended  with  soar  throat,  and  the  like,  are  so  apt  to  pro- 
duce transient  or  permanent  deafness. 

519.  In  the  first  place,  the  tube  is  so  small  that  any  little  thickening 
of  its  lining  will  close  it.  This  may  take  place  and  the  sides  of  the 
tube  not  adhere,  or  they  may  grow  together.  To  know  if  the  tube 
be  closed,  compress  the  nostrils  and  shut  the  mouth,  then  blow  with 
force.  If  the  tube  be  open,  the  air  will  be  forced  into  the  drum  B,  and 
distend  the  membranes  outward.  This  will  produce  a  sensation  of 
feeling,  and  usually  a  crackling,  or  a  rumbling  sound.  If  *he  tube  be 
closed,  nothing  of  the  kind  will  take  place.  To  know  if  the  tube  be 
permanently  closed,  it  will  be  seen  by  Fig.  77,  that  a  probe  may  be 
passed  along  the  floor  of  the  nasal  cavity  to  its  back  part,  when  the 
probe,  if  turned  inward  and  downward  at  the  outer  extremity,  will  be 
turned  upward  and  outward  at  its  inner  extremity,  and  enter  the  tube. 
This  by  the  skilful  physician  can  be  readily  done.  If  the  probe  can  be 
passed  into  the  ear-drum  without  causing  pain,  time  after  time  it  can 
be  done,  and  with  the  use  of  larger  probes,  till  at  last  the  opening  will 
remain  when  the  probe  is  removed,  and  the  air  is  again  allowed  a  passage 
into  the  ear,  and  the  collections  of  the  ear  a  passage  out.  In  such  a 
case,  very  great  care  must  be  taken  to  avoid  colds,  as  the  slightest  causes 
will  tend  to  close  the  tube  again. 

Fig.  77. 


Fig.  77. — Represents  a  section  of  the  nose  upon  one  side  of  the  division  or  vomer, 
the  turbinated  (coiled)  bones  are  seen  with  a  portion  removed.  The  line  A,  TO,  extends 
to  the'  op«ning  of  the  Eustachiau  tube,  m. 


SEC.  3.]  ORGANS  OF  SENSE.  189 

520.  If  the  tube  be  permanently  closed,  it  has  been  sometimes  pro- 
posed to  make  an  opening  through  the  external  membra  "ic.     By  this 
means,  air  of  course  would  be  admitted  to  the  drum  of  the  e&r,  but  there 
would  be  no  chance  for  the  collections  of  the  ear  to  pass  off,  and  the 
result  of  such  experiments  has  proved  unsatisfactory. 

521.  The  membrane  lining  the  ear-drum,  and  also  the  mastoid  cells, 
is  subject  to  a  variety  of  diseases.     Its  lubricating  fluids  are  not  formed 
in  sufficient  quantity  at  times,  and  the   membrane  becomes  dry,  and 
where*  it  covers  the    drum-heads,  it  would,  of  course,  diminish   their 
flexibility.     Again,  at  times  the  fluids  of  the  ear-drum  are  formed,  in 
superfluous  quantities,  and  injury  ensues.  "  The  lining  of  the   drum  is 
thickened  and  the  consequences  are  bad,  etc.     If  hardness  of  hearing 
depend  upon  want  of  flexibility  of  the  membranes,  it  can  be  determined, 
many  times,  by  the  history  of  the  case,  and  by  the  kinds  of  sounds 
heard  most  distinctly.     If  a  child's  voice  be  heard  readily,  while  the  low 
voice  of  manhood  is  heard  with  difficulty,  the  hardness  of  hearing  may 
be  attributed,  in  many  cases,  to  inflexibility  of  the  membranes.     The 
physician  can,  in  many  cases,  by  proper  injections  and  attention  to  the 
general  health,  restore  health  to  the  lining  of  the  ear-drum.     It  is  some- 
times very  beneficial  where  the  membranes  are  inflexible  to  close  the  nose 
and  mouth,  and  then  -alternately  blow  the  air  into  the  ear-drum,  and 
allow  it  to  return.     This  will  throw  the  membranes  into  motion,  and  by 
frequent  repetition   tend   to   give    them   suppleness.      If,  however,  the 
slightest  pain  is  thus  produced,  the  course  should  not  be  pursued. 

522.  An   arm  of  a   small   bone  called   the   malleus  (hammer),  a, 
is  attached  to  the  membrane,  just  below  its  centre,  as  seen  in  Fig.  76. 
The  head  of  the  hammer  is  attached  to  another  bone  called  the  incus 
(anvil).     This  has  by  some  been  thought  to  resemble  a  tooth  with  two 
fangs,  one  larger  than  the  other,  and  considerably  separated  from  it. 
To  the  longer  branch  or  arm  of  this  bone,  a  very  small  bone,  called  the 
orbicularis  (round  bone),  c  is  attached.    By  some  it  is  considered  as  a  part 
of  the  anvil-shaped   bone,  as  it  is  inseparably  attached  to  it  after  the 
period  of  childhood.     It  is  only  about  as  large  as  the  flattened  head  of 
a  pin.     The  fourth  bone  from  its  form,  called  the  stapes  (stirrup),  d,  is 
attached  to  the  round  bone  by  one  part,  and  exactly  covers  the  oval  hole 
(2,  Fig.  76). 

523.  The  bones  are  jointed  together  in  such  a  manner  as  to  move 
upon  each  other.     When,  therefore,  the  slightest  movement  is  produced 
in  the  first  membrane,  it  will  be  communicated  to  the  chain  of  bonea 


190 


ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

Fig.  78. 


IIIIIIB         '..'"     !!iI|Sliilllllf!iIili 


JF 


Fig.  78 — The  bone  of  the  ear,  1,  malleus  (hammer),  2.     The  upper  one  is  called 
incus  (anvil),  the  lower  one  orbicularis  (round).    3,  Stapes  (ptirrup). 


Fig.  79. 


Fig  79. — Represents  a  section  of  the  bone  containing  the  drum  of  the  ear  in  which 
the  bones  are  seen. 

stretching  across  to  membrane  2.     Each  movement  of  the  first  membrane 
will,  therefore,  act  upon  membrane  2. 

524.  It  is,  however,  certain  that  persona  have  lived  and  enjoyed 
their  hearing  well  where  the  bones  were  wanting.  They  are  not,  there- 
fore, absolutely  essential.  By  some  it  is  thought  that  hearing  is  usually 


SEC.  3.]  ORGANS  OF  SENSE.  191 

produced  by  the  communication  that  takes  place  through  the  air,  between 
membranes  1  and  3.  Others  think  that  communications  will  always  be 
made  through  the  air  between  1  and  both  2  and  3,  and  that  the  bones 
are  merely  of  use  to  produce  a  proper  state  in  the  membranes,  in  respect 
to  tensity,  etc.  Others  again  think  that  communications  are  made  from 
1  to  2  by  the  bones,  and  from  1  to  3  at  the  same  time  by  the  air.  Others 
think  that,  ordinarily,  communication  is  established  by  the  bones,  but 
when  the  bones  are  wanting  the  air  is  the  medium.  It  is,  therefore,  by 
no  means  certain  how  beneficial  or  necessary  the  bones  are.  There  is 
no  doubt  in  my  mind  that  they  are  of  use,  and  that  want  of  proper 
motion  at  the  joints  where  they  are  united}  renders  hearing  indistinct ; 
and  to  preserve  facility  of  motion  between  the  bones,  the  same  things 
may  be  recommended  as  in  case  of  inflexibility  of  the  membranes. 

525.  A  muscle,  worthy  of  note,  extends  from  the  vicinity 
of  the  Eustachian  tube  to  the  hammer.     By  contraction,  it 
can  make  the  membrane  1  more  or  less-  tense. 

Some  suppose  that  the  membrane  must  be  tuned,  so  to  speak,  to  the 
various  waves  acting  upon  it — for  instance,  that  the  waves  producing  an 
acute  sound,  are  met  by  a  tense  state  of  the  membrane  ;  while  a  wave 
producing  a  low  or  gruff  sound,  is  met  by  a  lax  or  slackened  state  of  the 
membrane.  It  is  uncertain. 

526.  The  membranes  covering  the  oval  and  round  holes, 
called  also  fenestra  (windows),  separate  the  ear-drum  from 
the  labyrinth.     This  is  worked  out  of  the  very  solid  bone, 
and  consists  of  three  parts,  called  the  vestibule  (porch),  semi- 
circular (half-circle)   canals,  and   the  cochlea   (snail-shell) 
(Fig.  80,  and  Fig.  81). 

The  particular  use  of  these  parts  is  not  known.  The  general  princi- 
ple by  which  hearing  is  produced,  can  be  better  obtained  from  Fig.  76, 
where  a  circular  box  represents  the  entire  labyrinth. 

527.  The  labyrinth   is  lined  throughout  with   a  skin  or 
membrane,  adhering  closely  to  the  bone  by  one  side ;   but 
very  smooth  and  delicate  upon  the  other,  like  the  free  surfa'ce 
of  a  serous  membrane.     Upon  this  surface  is  poured  out  a 
limpid  fluid,  called  the  aqueous  (watery)  humor  of  the  ear. 
It  fills  the  labyrinth. 


192  ORGANS  OF  SENSATION  OR  FEELING.  [dlAP.  II. 

Fig.  80. 

^e&=^ 

X. 


Fig.  80. — The  labyrinth;  V,  ventricle  ;  O,  foramen  ovale;  R,  foramen  rotundum; 
A,  A,  ampullae ;  z,  z,  semicircular  canals ;  K,  cochlea. 

528.  la  the  midst  of  this  fluid,  in  the  vestibule  and  semi- 
circular canals,  is  formed  a  membranous  bag  or  pouch,  taking 
the  form  of  the  parts  in  which  it  is  found ;  but  not  touching 
the  sides  of  the  labyrinth,  except  at  certain  parts,  as  at  ?/,  Fig. 
76,  where  the  lining  of  the  labyrinth  is  reflected,  as  it  is  said, 
to  form  the  external  layer  of  the  bag.     The  bag  is  filled  by  a 
fluid  similar  to  that  outside  of  it,  and  formed  by  its  inner  coat 
or  lining.     The  sac,  however,  is  exceedingly  delicate,  and 
has  been  compared  to  the  retina  of  the  eye  for  delicacy,  but 
is  more  firm. 

529.  Jn  this  sac  sometimes,  and  in  the  fluid  outside  of  it, 
a  powder,  like  powdered  bone,  is  found.     Sometimes  it  is  so 
coarse  as  to  resemble  sand,  or  collected  so  as  to  form  tiny 
stones. 

Its,  or  their  use,  is  not  known. 

530.  The  nerve  of  hearing  passes  to  the  bag  and  also  to 
the  lining  of  the  labyrinth  in  the  cochlea,  where  it  divides 
and  subdivides,  terminating,  as  some  say,  at  the  very  surface 
— or  perhaps,  as  others  say — projecting  a  little  into  the  fluid, 


SEC.  3.J 


ORGANS  OF  SENSfi. 

Fig.  81. 


193 


Fig.  81.— Section  of  the  labyrinth,  drum  of  the  ear,  and  external  tube  a— closed  by 
a  membrane,  to  the  inner  surface  of  which  the  hammer  c  is  attached ;  cf,  the  anvil ;  c, 
the  round  bone  connecting  the  anvil  with  the  stirrup ;  g-,  the  semicircular  canals ;  h, 
the  cochlea ;  f,  the  passage  of  the  nerve. 


and  as  it  seems  very  near  the  surface,  in  delicate  papillae, 
represented  by  x,  in  Fig.  76. 

531.  The  movements  of  either  or  both  membranes,  will 
produce  waves  in  the  fluid  of  the  labyrinth  and  its  inclosed 
bag ;  which  dashing  upon  the  surfaces  containing  the  points 
of  the  nerves,  will  cause  impressions  as  various  as  the  pro- 
ducing causes. 

532.  The  minute  circumstances  to  be  regarded  in  producing  perfect 
hearing,  are  not  understood.  It  is  however  evident  enough  that  a  proper 
supply  of  prpper  fluid  is  necessary.  It  is  probable  that  this,  like  most 
if  not  all  other  fluids  in  the  body,  is  undergoing  constant  change  by  fre- 
quent removal  and  as  frequent  formation  by  the  lining  of  the  labyrinth, 
and  the  covering  and  lining  of  the  bag.  If  it  be  either  removed  or 
9 


194  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  IT. 

formed  too  rapidly,  defective  hearing  must  be  one  of  the  consequences. 
It  may  likewise  become  too  thick,  or  by  some  disease  of  the  inclosing 
bones  or  membranes,  it  may  be  allowed  to  flow  out,  when  hearing  would 
of  course  be  lost.  The  membranes  also,  in  which  the  nerves  are  distrib- 
uted, may  become  thick  and  affect  hearing. 

533.  To  know  whether  the  contents  of  the  labyrinth  be  affected,  a 
watch  may  be  placed  in  several  positions  on  the  affected  side  of  the 
head.     If  the  ticking  be  heard  distinctly,  assurance  is  bad,  that  the  laby- 
rinth and  its  contents  are  not  affected,  for  the  bones  of  the  head  conduct 
the  vibrations  of  the  watch  to  the  labyrinth.     But  if  all  be  silent,  hope  is 
lost.     Hearing,  as  dependent  on  the  condition  of  the  nerve,  will  be  spoken 
of  hereafter. 

534.  With  such  a  multitude  of  causes  to  affect  hearing,  it  is  no  won- 
der that  we  find  many  people  deficient  in  this  respect,  or  that   deafness 
often  baffles  the  skill  of  the  most  skilful,  or  that  the  ears  which  hear  well 
should  yet  have  such  imperfection,  that  there  should  be  a  slight  difference 
in  the  sounds  produced  through  the  different  ears  of  the  same  person. 
The  wonder  is,  that  the  ears  should  be  so  generally  perfect.     The  most 
hasty  glance  at  this  subject  will  convince  any  one,  that  as  there  are  so 
many  causes  of  deafness,  those  who  warrant  or  advertise  their  oils  as 
sure  cures  for  deafness,  are  uripardonably  ignorant  or  most  arrant  scoun- 
drels, or  probably  something  amphibious  in  this  respect. 

535.  I  cannot  better  conclude  this  sketch  of  the  ear,  than  by  quoting 
from  Le  Cat's  most  excellent  treatise  on  the  senses.     "  Life,  deprived 
of  sensations  as  valuable  as  those  of  hearing,  would  be  a  kind  of  prema- 
ture death.     The  deaf  man  is  necessarily  a  dumb  man,  and  who  can 
compute  hia  loss?     His  never-sleeping  guard*  that  warned  him  of  a 
thousand  dangers  is  dead.     And  now,  the  crash  of  the  falling  tree,  the 
scream  of  the  drowning  child,  the  tread  of  the  midnight  thief,  and  the 
mutterings  of  the  coming  storm,  fall  on  his  ear  as  vainly  as  the  tear  of 
sorrow  on  the  brow  of  death.     Who  can  compute  his  loss  ?     The  sweet 
echoes  of  the  valley,  the  voice  of  friendship,  the  hallelujahs  of  the  Sabbath, 
and  the  loud  artillery  of  heaven,  are  alike  condensed  into  barren  nothing- 
ness, and  in  the  very  excess  of  stillness  he  loses  all  the  pleasures  of  soil- 
tude." 

*  Not  quite  correct,  for  the  sense  of  hearing  is  at  times  "  hushed  *a 
death-like  sleep." 


SEC.  4.]  THE  NERVES  OF  SENSATION.  195 


SECTION  4. — The  Nerves  of  Sensation. 

536.  These  are  white  pulpy  cords  extending  from  the 
organs  of  sense  to  the  brain.     They  look  very  much  like  the 
nerves  of  motion,  heretofore  described. 

Some  think  the  nerves  of  motion  terminate  in  the  nerves  of  sensation 
forming  loops  and  a  circuit  with  them.  But,  as  often  said,  the  commence- 
ments of  the  nerves  are  so  minute,  it  is  impossible  with  present  means,  to 
learn  how  they  commence.  The  word  commence  is  used,  because  in 
ordinary  cases,  the  portion  of  nerve  found  in  the  organ  of  sense  is  the 
part  first  acted  on. 

537.  It  is  the  duty  of  the  nerves  to  be  acted  on  by  cer- 
tain causes,  and  then  to  act  on  the  brain  and  cause  sensa- 
tions. 

When  the  right  kind  of  objects  act  on  the  organs  of  sense  in  a  healthy 
condition,  an  effect  is  produced  at  the  brain,  if  the  nerves  be  entire, 
healthy,  and  not  compressed  ;  but  the  instant  the  nerves  extending  from 
any  organ  of  sense  to  the  brain  are  cut,  or  compressed,  or  diseased  in 
certain  ways,  no  effect  can  be  produced  by  acting  on  that  organ  of  sense. 
This  shows  that  nerves  are  the  agents  through  which  effects  are  produced 
on  the  brain,  and  will  also  teach  what  particular  nerves  are  agents  in  the 
production  of  any  particular  sensation.  For  instance,  there  are  two 
nerves  extending  from  the  lining  of  the  nose  to  the  brain.  If  one  be 
cut  the  animal  cannot  smell,  but  feels  pain  if  the  lining  be  pricked,  while 
vice  versa,  if  the  other  nerve  be  cut  while  the  first  remains  entire  the 
animal  cannot  feel  pain  if  the  lining  be  pricked,  but  can  smell  as  well  as 
ever.  This  teaches  that  one  nerve  is  the  nerve  of  smell,  and  that  the 
other  is  the  nerve  of  common  feeling. 

538.  Some  causes  act  only  on  certain  nerves,  while  other 
causes  act  on  other  nerves. 

For,  as  just  shown,  the  nerve  of  smell  produces  no  effect  when  it  ifl 
pricked  ;  so  the  cause,  which  through  some  nerves  produces  tickling,  pro- 
duces no  apparent  effect  on  other  nerves.  Light  can  and  does  act  through 
the  outer  layer  of  the  skin,  but  without  producing  an  effect  of  sensation. 

539.  Some   causes    act   upon   all   the   nerves,   or  upon 


198  ORGANS  OF  SENSATION  OR  FEELING.          [CHAP.  II. 

several,  producing  different  effects  and  causing  different  sen- 
sations. 

Electricity,  as  it  is  called,  will  act  upon  the  nerves  passing  from  the 
organ  of  taste,  and  the  sensation  caused  is  the  same  as  if  a  person  were 
tasting  something.  If  it  act  on  the  nerve  of  smell,  a  sensation  of  smell 
is  perceived.  If  it  ac.  on  the  nerve  of  hearing,  a  sensation  of  sound  is 
produced.  If  it  act  on  the  nerve  of  sight,  the  sensation  of  light  is  pro- 
duced. If  it  act  upon  other  nerves,  other  sensations  will  be  produced. 
If  a  person  falling,  strike  the  head  violently,  the  jar  acts  on  several,  per- 
haps all  the  nerves,  so  as  to  produce  sensations,  differing  in  case  of  the 
different  nerves  ;  thus  a  person  "  sees  stars,"  hears  a  sound,  perceives  a 
smell,  and  through  other  nerves  has  sensations  of  pain,  of  "jarring,"  &c., 
produced.  From  the  previous  paragraph  as  well  as  this,  it  follows,  that 
as  some  of  the  nerves  are  acted  upon  by  causes  having  no  effect  on  other 
nerves,  and  as,  when  the  same  cause  does  produce  effects  through  differ- 
ent nerves  the  effects  are  different, 

540.  The  different  nerves  are  differently  constituted,  and 
are  intended  to  produce  certain  kinds  of  sensations,  whatever 
may  be  the  causes  acting  upon  them. 

This  is  an  exceedingly  interesting  and  important  proposition,  and  a 
few  more  illustrations  may  be  brought  forward.  If  a  nerve  in  the  finger 
be  pricked,  it  produces  a  sensation  of  pain  ;  but  if  the  nerve  of  smell  be 
cut,  it  causes  a  sensation  of  smell ;  if  the  nerve  of  taste  be  pricked,  it 
causes  a  sensation  of  taste.  If  the  nerve  of  sight  be  cut,  as  is  sometimes 
necessary  in  extirpating  the  eye,  a  sensation  of  a  great  flash  of  light  is 
caused.  If  the  eye  be  pressed,  two  sensations  are  at  once  produced 
through  two  different  nerves.  Pressure  through  the  eye  on  the  nerve  of 
sight  produces  a  sensation  of  light,  while  pressure  on  the  nerve  of  com- 
mon feeling,  extending  from  the  eye  to  the  brain,  produces  an  unpleasant 
or  painful  sensation.* 


*  Thus  it  is  seen  that  the  nerves  are  so  made,  that  the  sensation  of 
light  can  only  be  produced  through  the  nerve  of  sight,  and  through  its 
agency  only  can  a  person  see.  It  has  been  seen  in  a  previous  section, 
that  a  person  distinguishes  objects  only  by  the  color  of  the  light  they 
cause  to  act  on  the  nerves,  and  by  the  direction  in  which  the  light  comes, 
for  which  purposes  the  eye  is  necessary.  Since  the  eye  and  nerve  of  sight 
are  both  necessary  that  a  person  may  see,  how  absurd  it  is  for  persons  to 
pretend  to  see  through  the  pit  of  the  stomach,  their  fingers'  ends,  the  top 


SEC.  4.]  THE  NERVES  OF  SENSATION.  197 

541.  There  is  one  other  respect  in  which  the  nerves  are 
peculiar.    Some  causes  act  only  at  the  commencement  of  the 
nerves,  other  causes  act  upon  any  part  brought  within  the 
sphere  of  their  influence. 

If  any  peculiar  temperature  act  on  the  commencement  of  a  nerve  it 
produces  effects,  but  only  by  acting  on  the  commencement.  For  instance, 
the  temperature  acting  on  the  foot  produces  an  effect  on  the  brain,  but 
the  nerve  extending  from  the  foot  to  the  brain  is  acted  upon  by  a  great  va- 
riety of  temperatures  at  different  points,  but  they  produce  no  effect.  How 
wise  this  provision  is!  Had  it  been  otherwise,  the  variety  of  sensations 
produced  through  any  nerve  would  have  entirely  confused  the  mind,  and 
no  idea  of  the  state  of  the  foot  could  have  existed.  If,  however,  the 
same  nerve  be  cut,  a  sensation  will  be  produced  similar  in  all  cases, 
whether  the  nerve  be  cut  in  the  foot  or  in  some  other  part  of  its-  extent. 
It  is  thus  with  all  the  nerves ;  viz.,  cut  them  in  any  point  of  their  course, 
and  they  will  produce  like  results  as  if  cut  at  any  other  point.  If  elec- 
tricity act  on  the  nerve  at  any  point  of  its  course,  it  produces  the  same 
result  as  if  it  acted  at  any  other  point  of  it. 

To  sum  up  the  whole  matter,  therefore,  it  is  seen  that  some  objects 
act  on  one  nerve  and  some  on  another,  while  some  things  act  on  all 
the  nerves  ;  that  some  causes  act  on  the  nerves  at  their  commencement 
only,  while  other  causes  can  produce  effects  if  they  act  on  any  part  of 
the  nerves ;  and  that, 

542.  The  kind  and  degree  of  effect  produced  on  the  brain 

of  the  head,  &c.,  as  some  impostors  assert  they  do.  Says  Muller — "  So 
long  as  a  magnetic  patient  manifests  merely,  the  ordinary  phenomena  of 
nervous  action  that  are  seen  in  other  disorders  of  the  nervous  system,  it 
is  all  credible  enough  ;  but  when  such  a  person  pretends  to  see  through 
a  bandage  placed  before  the  eyes,  or  by  means  of  the  fingers  or  the  epi- 
gastrium (upon  the  stomach),  or  see  round  a  corner  and  into  a  neighbor- 
ing house,  or  to  become  prophetic,  such  arrant  imposture  no  longer  de- 
serves forbearance,  and  an  open  and  sound  exposure  of  the  deception  is 
called  for."  That  such  things  may  be  done,  it  should  be  remembered,  not 
only  must  a  person  be  magnetized,  but  also  the  laws  by  which  the  Cre- 
ator has  ordained  that  light  shall  be  governed.  It  is  to  be  hoped  as  we 
attribute  the  ignorance  of  our  ancestors  to  the  times  in  which  they  lived, 
and  pardon  them  for  believing  in  witches,  and  hanging  those  who  were 
"  plainly  proved  to  be  leagued  with  the  Prince  of  Darkness,"  that  a  more 
enlightened  future  generation  will  not  reflect  too  severely  on  their  fore- 
fathers for  their  credulity  in  respect  to  clairvoyants,  quack  pills,  &c.,  of 
the  present  day. 


198  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

ty  any  nerve,  acted  upon  at  any  point  by  any  cause,  depends 
on  the  NATURE  and  STATE  of  the  nerve  acted  on. 

543.  The  nature  of  the  nerve  determines  the  kind  of  effect 
produced  when  action  of  the  nerve  is  produced. 

For  instance,  the  nerve  of  hearing  cannot  produce  a  sensation  cf 
light,  neither  can  the  nerve  of  sight  cause  a  sensation  of  sound,  and  the 
other  nerves  are  by  their  nature  able  to  produce  only  their  peculiar  kinds 
of  sensation.  Each  nerve  of  any  class  of  nerves  can  of  course  produce  a 
variety  of  sensations,  but  all  of  one  kind  ;  that  is  to  say,  every  nerve  ot 
the  class  is  able  to  produce  any  sensation  that  any  other  nerve  cf  the 
class  can,  for  the  instant  any  nerve  produces  any  sensation  or  is  the  agent 
in  producing  any  sensation,  which  another  nerve  cannot  produce,  it  must 
be  classed  separately  from  the  other  nerve.  For  instance,  all  the  nerves 
of  sight  can  produce  the  sensation  of  light  and  all  the  varieties  of  that 
kind  of  sensation,  but  cannot  produce  the  sensation  of  sound ;  while  all 
the  nerves  of  hearing  can  produce  the  sensation  of  hearing,  but  cannot 
cause  the  sensation  of  light ;  and  though  the  nerve  may  have  its  condition 
altered  so  as  to  produce  different  varieties  of  sensations  of  its  own  kind, 
and  with  different  degrees  of  intensity,  if  a  nerve  act  at  any  time  it 
must  produce  sensations  of  its  own  kind. 

544.  The  state  of  the  nerve  will  determine  the  degree 
and  variety  of  effect  it  will  produce  on  the  brain. 

545.  The  state  of  the  nerve  is  either  natural  or  culti- 
vated. 

546.  Natural.     The  state  of  one  person's  nerves  is  naturally  such  that 
a  slight  cause  produces  a  powerful  effect    The  state  of  another  person's 
nerves  is  such  that  a  powerful  cause  will  produce  only  a  slight  effect.    In 
other  persons  slight  causes  act  through  some  nerves  and  produce  intense 
sensations,  while  powerful  causes  act  through  other  classes  of  nerves  with- 
out much  effect.     Persons  do  not,  therefore,  perceive  similar  sensations 
under  the  same  circumstances. 

547.  Cultivated  or  artificial.    Disease  will  alter  the  state  of  the  nerves 
to  such  a  degree  that  sometimes  they  produce  sensations  without  the  action 
of  any  other  cause.     For  to  produce  a  sensation  it  is  not  necessary  that 
any  thing  act  on  the  nerve,— only  a  certain  state  of  the  nerve.     Usually, 
to  be  sure,  some  cause  acts  on  the  nerve  and  produces  the  state  which 
causes  the  nerve  to  produce  an  effect  on  the  brain  ;  but  if  disease  pro- 


SEC.  4.]  THE  NERVES  OF  SENSATION.  199 

duce  the  same  or  a  similar  state  of  the  nerve,  the  sensation  will  be  pro- 
duced. To  illustrate  ;  wood,  coal,  oil,  spirits,  slaking  lime,  or  aught  else 
may  be  used  to  cause  water  to  boil,  it  matters  not.  The  water  boils 
when  it  is  in  a  certain  state,  viz.,  when  it  is  hot  enough,  and  whatever 
brings  it  into  that  state  will  cause  it  to  boil.  So  a  disease,  a  cut,  electri- 
city, or  the  more  usual  cause,  may  cause  a  nerve  to  produce  a  sensation ; 
if  acting  on  the  nerve  any  where,  they  produce  a  certain  state.  Some- 
times disease  does  not  produce  such  a  state  that  sensations  are  produoed, 
but  such  a  state  that  a  slight  cause  will  produce  sensations.  To  illus- 
trate again  ;  if  the  water  be  very  hot,  only  a  little  wood  will  be  neces- 
sary to  cause  it  to  boil.  Thus  a  student  by  much  study  and  neglect  of 
exercise,  many  times  produces  such  a  state  of  the  nerves  of  sight  that 
the  action  of  only  a  little  light  proves  very  unpleasant.  Diseases  in  some 
instances  produce  such  a  state  of  the  nerves,  that  very  powerful  causes 
produce  only  slight  effects.  Diseases  are  so  peculiar  in  their  effects,  that 
the  state  of  the  nerve  necessary  to  produce  certain  varieties  of  sensation 
is  very  easily  produced,  or  with  great  difficulty.  That  is,  the  nerve  of 
sight  is  very  easily  acted  upon  by  causes  of  certain  colors,  the  nerve  of 
hearing  by  causes  of  certain  sounds,  certain  kinds  of  odors  easily  produce 
a  powerful  effect,  or  vice  versa.  These  nerves  are  deficient  only  in  respect 
to  certain  varieties  of  sensations  of  the  kinds  peculiar  to  each.  Some  per- 
sons are  thus  affected  naturally  or  by  disease,  very  early  in  life,  and  to  such 
a  degree  that  certain  colors  do  not  produce  any  or  at  least  not  a  usual  effect, 
and  they  **  see  things  differently  from  other  folks."  Others  are  affected 
in  such  a  way  they  do  not  hear  certain  sounds  at  all,  or  smell  certain 
odors,  etc.,  etc. 

548.  Medicines  produce  like  effects  with  those  just  des- 
cribed. Some  medicines  will  produce  such  a  state  of  the 
nerves  that  the  slightest  cause  will  excite  sensations,  or, 
perhaps  sensations  will  be  produced  without  any  other  cause, 
or,  on  the  other  hand,  produce  such  a  state  in  the  nerves 
that  no  effect,  or  but  slight  effect,  can  be  produced  by  the 
most  powerful  causes.  This  is,  of  course,  highly  beneficial 
when  it  can  be  done  without  retarding  nature  in  her  efforts 
to  produce  a  cure.  The  slamming  of  doors,  and  all  the  like 
aggravations  of  disease,  of  course  are  comparatively  harm- 
less when  the  state  of  the  nerves  is  such  that  but  a  slight 
sensation  can  be  produced. 


200  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

549.  Various  kinds  of  food,  and  indeed,  the  whole  manner  of  living, 
will  either  exalt  or  depress  the  state  of  the  nerves  in  such  manner  that 
the  sensations  will  be  easily  or  with  difficulty  produced.  Thus  it  is  in 
our  power  to  produce,  within  limited  bounds,  such  a  state  of  the  nerves, 
that  the  causes  acting  upon  them  shall  produce  such  sensations  as  are 
desirable. 

Let  us  now  give  our  attention  to  the  kinds  of  nerves,  viz.,  those 
which  produce  similar  sensations. 

550.  a.  The  first  pair  of  nerves  of  sensation  is  called 
the  olfactory.  They  extend  from  the  brain  forward  over 
the  nose,  where  little  branches  pass  down  through  the  sieve- 
like  holes  in  the  bone  forming  the  roof  of  the  nose,  and  ter- 
minate, or  rather  commence  in  the  lining  of  the  nose,  as 
heretofore  described,  and  represented  at  Fig.  82. 

Fig.  82. 


Fig.  82.— Represents  a  section  of  the  nose  parallel  with  its  natural  division.  From 
4,  a  line  reaches  down  to  the  olfactory  nerve,  or  what  is  sometimes  called  the  olfac- 
tory lobe  of  the  brain.  From  it  the  nerves  are  seen  passing  thiough  the  cribriform 
(sieve-like)  portion  of  the  ethmoid  bone.  The  other  portions  do  not  need  mention. 

Properly  speaking,  however,  that  which  extends  from  the  brain  over 
the  roof  of  the  nose,  should  be  called  a  part  of  the  brain,  or  the  olfac- 
tory lobe  of  the  brain.  It  is  in  fishes  the  largest  portion  of  the  brain. 
The  branches  which  come  down  into  the  nose  should  be  considered  as 
the  nerves  of  smell. 

551.  b.  The  second  pair  of  nerves  of  sensation,  are  the 
nerves  of  sight,  called  the  optic  nerves.  When  they  leave 


SEC.  4.]  THE  NERVES  OF  SENSATION.  201 

the  eyes,  they  seem  as  if  composed  of  millions  of  fibres  col- 
lected  in  one  bundle,  and  covered  with  a  sheath,  which  is  con- 
tinuous on  the  one  part  with  the  dura-mater  of  the  skull,  and  on 
the  other  extremity  with  the  white  of  the  eye.  It  is  supposed 
that  every  nervous  point  in  the  retina  is  the  commencement 
of  a  nervous  fibre,  which  assists  to  compose  the  optic  nerves. 
452.  A  little  back  from  the  eyes,  the  nerves  from  each 
eye  meet,  and  a  part  of  the  fibres  from  each  pass  across,  viz., 
that  half  of  the  fibres  towards  each  other  oass  acvss  between 
each  other,  when  the  nerves  go  on  to  the  brain,  with  which 
they  do  not  immediately  unite  ;  but  as  if  there  were  a  neces- 
sity for  them  to  produce  effecte  at  a  certain  part  of  the  brain, 
they  wind  around  and  terminate  at  the  inner,  middle  and 
lower  parts  of  the  brain  (Fig.  83). 


Fig.  83. 


Fig.  83.— 1,  The  external  or  sclerotic  coat  of  the  eye  with  the  cornea  at  the  front 
part.  2,  The  choroid  coat  with  the  ciliary  processes  at  the  front  part.  6,  The  com- 
missure of  the  optic  nerve,  showing  the  crossing  of  the  nervous  fibres.  The  lower 
portion  of  the  brain — the  commencement  of  the  spinal  cord,  and  the  roots  of  tha 
nerves,  are  easily  recognized. 

Q* 


202  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

653,  c.  The  third  pair  of  nerves  of  sensation  commence 
at  the  ears,  and  are  immediately  brought  in  contact  with  the 
nerves  called  facial,  which  are  nerves  of  motion ;  by  the  side 
of  these  they  pass  back  to  the  brain. 

554.  d.  The  fourth  pair  of  nerves  of  sensation  are  called 
the  nerves  of  taste.     But  at  present  it  is  not  determined 
which  nerve  is  the  nerve  of  taste.     Some  suppose  one,  some 
suppose  another ;  there  being  several  nerves  commencing  in 
the  tongue,  which  extend  to  the  brain,  and  experiment  has 
not  yet  decided  to  which  to  give  the  preference. 

555.  e.  The  nerves  of  the  muscular  sense  are  very  numerous,  and 
are  so  combined  with  the  nerves  of  common  feeling,  that  they  may  be 
considered  as  part  of  them,  so  far  as  it  regards  their  structure,  arrange- 
ment, and  terminations  at  the  brain. 

556.  /.  The  nerves  of  common  feeling.     These  are  very  numerous, 
and  in  fact  embrace  several  kinds  of  nerves,  which  are  called  by  the 
same  general  name,  either  because  their  duties  are  not  worthy  of  par- 
ticular notice,  or  because  they  are  so  blended  with  other  kinds  of  nerves 
that  it  is  not  possible  to  distinguish  them  by  experiment  or  examination. 
Indeed,  in  most  cases  they  are  so  similar  to  the  nerves  through  which 
motion  is  produced,  and  so  blended  with  them,  that  it  is  not  possible  to 
distinguish  in  the  greater  part  of  their  course,  the  nerves  of  feeling  from 
the  nerves  of  motion.     Indeed,  till  within  a  few  years,  it  was  thought 
that  the  same  nerves  fulfilled  two  agencies  at  once,  viz.,  that  they  were 
the  agents  for  producing  motion,  and  also  sensation. 

557.  The  nerves  of  common  feeling  —  including  the 
nerves  of  the  muscular  sense — commence,  so  far  as  can  be 
judged,  in  every  part  of  the  body,  each  nerve  in  its  particu- 
lar part. 

Not  excluding  those  parts  in  which  commence  the  nerves  already 
mentioned,  and  called  for  distinction  sake — special  nerves  of  sense  ; 
they  being  nerves  for  the  especial  purposes  already  signified.  In  some 
parts  of  the  body,  however,  the  nerves,  if  they  exist,  cannot  be  seen ;  and 
the  only  proof  of  their  existence  is,  that  they  are  the  causes  of  sensation — 
which,  from  what  is  known,  is  supposed  to  be  always  produced  through 
the  Agency  of  nerves. 


SEC.  4.] 


THE  NERVES  OF  SENSATION, 


203 


558.  Immediately  after  the  nerves  commence,  they  begin 
to  unite  with  each  other  in  such  way  that  they  are  found  by 
the  side  of  each  other,  but  yet  distinct  from  each  other ;   and 
in  the  same  manner,  they  unite  with  any  nerves  of  motion  in 
their  vicinity  till  at  last  large  trunks  are  formed,  which  may 
be  traced  into  the  back-bone,  or  through  the  skull  into  the 
head,  as  the  case  may  be. 

559.  Within  the  back-bone,  the  nerves  divide  into  two 
parts  called  the  anterior  (front),  and  posterior  (back)  roots, 
(Fig.  84).     Here,  but  a  few  years  ago,  Sir  Charles  Bell  and 
Magendie,  by  experiment,  discovered  the  double  nature  and 
duties  of  the  nerves.      If  the  front  root  of  the  nerves  of  a 
frog's  leg  be  cut,  he  cannot  move  the  leg,  because  he  has  no 
means  of  communicating  a  contraction-causing-influence  to 
the  muscles  of  the  leg ;  but  the  frog  appears  to  suffer  pain, 
if  the  leg  be  pricked. 

Fig.  84. 


Fig.  84. — Represents  the  double  roots  of  a  spinal  nerve,  with  a  ganglion  D  on  the 
back  or  posterior  root. 

560.  If  the  back  root  of  the  nerve  be  cut,  while  the  front 
root  is  entire,  the  animal  can  move  the  leg,  but  feels  no  pain 
when  the  foot  is  even  burned.  These  things  show  that  the 
front  roots  are  the  agents  through  which  motions  are  pro- 
duced, and  the  back  roots  the  agents  through  which  the  sen- 
sations are  produced. 


204  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

561.  The  posterior  roots  unite  with  the  spinal  cord,  at  a 
line  produced  by  the  gray  substance  coming  to  the  surface 
of  the  cord,  as  in  Fig.  43.     The  anterior  roots  unite  with  the 
sides  of  the  front  parts  of  the  cord  in  the  neck  ;   but  as  they 
unite  with  the  cord  lower  down,  they  unite  with  it  more  in 
front. 

562.  After  the  nerves  of  sensation  have  united  with  the 
spinal  cord,  it  is  impossible  to  trace  them  to  the  brain ;  and 
the  only  proof  that  they  extend  to  the  brain,  is  found  in  the 
proof  that  the  brain  is  the  seat  of  the  mind,  which  distin- 
guishes every  part  of  the  body  in  which  an  effect  is  pro- 
duced on  a  sensitive  nerve. 

563.  Some  have  supposed  that  they  could  distinguish 
two  parts  in  each  half  of  the  spinal  cord.  Sir  Charles  Bell 
thought  he  had  proof,  that  in  the  neck  at  least,  there  are 
three  columns,  as  he  termed  them,  in  each  half  of  the  cord, 
viz.,  the  front  column,  the  back  or  posterior  column,  and  a 
middle  column,  called  the  respiratory  tract.  Those  of  this 
opinion  think  the  front  column  is  composed  of  the  nerves 
forming  the  front  roots  of  the  nerves,  the  agents  in  producing 
motion ;  and  that  the  back  column  is  composed  of  nervous 
filaments  from  the  posterior  roots  of  the  nerves,  the  agents  in 
producing  sensation.  But  there  seems  to  be  such  an  inter- 
lacing and  blending  of  nervous  filaments  in  the  spinal  cord, 
that  it  is  not  possible  for  any  anatomist,  however  skilful,  with 
present  means,  to  separate  the  different  nerves  composing  the 
cord. 

564.  On  the  posterior  root  of  each  of  the  nerves  entering 
the  back-bone,  is  found  a  collection  of  reddish  gray  substance 
called  a  ganglion. 

The  use  of  this  part  is  not  known.  By  some  it  has  been  considered 
as  a  nervous  centre  in  which  some  effects  are  produced  on  the  nerves 
passing  through  it,  or  in  which  terminates  or  commences  some  effect. 
There  is  no  substantial  proof  of  any  of  the  hypotheses  so  liberally  ad- 


SEC.  5.]    THE  BRAIN  AS  AN  ORGAN  OF  SENSATION.       205 

vanced,  and  though  a  mortification  to  one's  pride,  truth  compels  the  ac- 
knowledgment that  their  use  is  unknown.  They  are  found  on  nearly,  if 
not  all  the  nerves  of  general  sensation. 

565.  Thus  it  might  be  expected,  as  is  the  case,  that  injury  to  the 
spinal  cord  at  any  point  would  prevent  any  sensations  from  being  pro- 
duced by  the  parts  below,  and  this  might  be  of  such  a  character  as  to 
affect  either  one  class  of  nerves,  or  the  other,  or  both.     The  injury  might 
affect  one  side  only  of  the  spinal  cord,  or  both  sides,  or  it  might  one  class 
of  nerves  on  one  side  and  the  other  class  on  the  other  side.     If  the  in- 
jury affected  only  a  few  fibres  of  the  cord,  a  corresponding  effect  would 
be  produced.     If  the  cord  were  injured  in  the  neck,  it  would  not  be  ex- 
pected that  the  nerves  entering  the  head  would  be  included  in  the  injury. 

566.  If  again,  any  such  cause  as  disease  or  injury  affected  the  nerves 
of  sensations  in  their  course  through  the  cord,  so  as  to  produce  certain 
states  of  the  nerve,  sensations  would  result  necessarily.* 


SECTION  5. — The  Brain  as  an  Organ  of  Sensation. 

567.  The  first  duty  of  the  brain  as  an  organ  of  sensa- 
tion, is  to  produce  effects  which  may  be  perceived  by  the 
mind,  and  which  are  called  sensations. 

Whether  the  brain  can  produce  any  effects  on  the  mind,  which  are 
not  felt,  is  not,  and  of  course  cannot  be  known.  We  know  that  persons 

*  From  the  remarks  in  this  section  it  might  be  inferred,  that  com- 
pression of  a  nerve  would  prevent  any  thing  acting  on  the  nerve  below 
the  compressed  point  from  producing  any  effect.  This  is  certainly  cor- 
rect. The  sensations  caused  when  a  nerve  is  compressed,  are  owing,  not 
to  any  effect  produced  on  the  organs  of  sense  of  the  nerve,  but  to  the 
state  produced  in  the  nerve  by  compression.  It  might  also  be  inferred, 
that  compression  of  the  proper  nerves  would  prevent  pain  in  case  of 
surgical  operations.  I  am  not  aware  that  any  experiments  have  been 
tried  which  would  show  whether  any  benefits  could  be  obtained  from 
such  a  course,  nor  has  any  opportunity  occurred  for  experiment,  since 
the  idea  suggested  itself,  except  on  animals,  in  which  case  no  pain 
seemed  to  be  produced  by  pricking,  cutting,  or  even  burning  the  foot, 
the  nerves  of  that  part  being  compressed.  Compression  of  the  nerve  in 
case  of  neuralgia,  has  been  suggested  and  tried,  in  case  of  neuralgia — 
and  it  would  seem  that  in  some  cases  amputation,  &c.,  might  be  done 
with  less  pain,  the  nerves  being  compressed. 


206  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

speak  to  us  without  our  knowing  it.  The  vibrations  of  the  voice  of  the 
speaker  must  reach  the  ear,  and  through  the  ear  effects  must  be  produced 
on  the  nerve  of  hearing,  and  it  would  seem  that  through  the  nerve 
effects  must  be  produced  on  the  brain,  but  whether  any  effect  is  produced 
on  the  mind  and  not  noticed,  or  whether  the  effect  stops  with  the  nerve 
or  the  brain  in  such  cases,  is  not  known. 

568.  The  first  duty  of  the  brain  is  proved  by  the  impor- 
tant fact,  that  sensations  depend  upon  the  state  of  the  brain. 

If  a  person  be  stunned,  the  state  of  the  brain  is  such  that  sensations 
cannot  be  produced.  Some  diseases,  such  as  apoplexy  and  many  other 
"  fits,"  some  medicines  such  as  opium,  intoxicating  draughts  of  alcohol, 
&c.,  produce  such  a  stupor  of  the  brain,  that  sensations  cannot  be  pro- 
duced. On  the  other  hand,  inflammation  of  the  brain,  and  various  medi- 
cines, in  small  or  large  quantities,  produce  such  a  state  of  the  brain,  that 
the  slightest  causes  will  produce  powerful  effects. 

569.  The  manner  in  which  this  duty  is  performed  is  not 
known. 

Some  suppose  that  the  nerves  through  which  various  parts  of  the 
body  cause  sensations  to  be  produced,  do  themselves  act  on  the  mind  ; 
that  in  other  words,  those  parts  of  the  brain  through  which  sensations 
are  produced,  are  composed  of  the  nerves  through  which  sensations  are 
caused.  Others  suppose  that  these  nerves  do  not  act  on  the  mind,  but 
on  distinct  parts  of  the  brain,  which  hold  communion  with  the  mind,  and 
transmit  effects  to  it  which  vary  as  the  effects  of  the  nerves  vary.  Others 
again  suppose,  that  the  nerves  terminate  at  one  part  of  the  brain,  it  may 
be  large,  or  it  may  be  small,  which  part  is  acted  on  differently  by  every 
different  state  of  the  nerves  producing  effects  thereon,  and  that  this  part 
transmits  effects  to  the  mind.  These  last  suppositions  involve  unneces- 
sary considerations,  it  seems  to  me  ;  besides,  I  cannot  conceive  how  the 
various  parts  of  the  body  can  produce  such  distinct  sensations  as  they 
do,  without  nerves  extend  from  every  point  capable  of  producing  sensa- 
tions to  the  mind  itself.  I  therefore  suppose  that, 

570.  Those  parts  of  the  brain  concerned  in  producing 
sensations  caused  by  any  part  of  the  body,  are  the  cerebral 
(brain)  extremities  of  the  nerves  of  sensation,  which  produce 
effects  on  the  mind  according  to  their  nature  and  state. 

The  same  remarks  which  applied  to  the  nerves,  in  Sec.  4,  will  apply 


SEC.  5.]    THE  BEAIN  AS  AN  ORGAN  OF  SENSATION.        207 

to  the  brain  in  the  fulfilment  of  its  present  duty  ;  for  so  much  of  the  brain 
as  is  under  present  consideration,  is  but  the  continuation  of  the  same 
nerves  there  spoken  of.  Indeed  it  will  make  no  difference  in  relation  to 
the  application  of  those  remarks,  what  philosophy  is  chosen,  though  it 
will  perhaps  do  no  harm  to  repeat,  with  slight  variation,  the  principles 
there  laid  down  ;  for  all  will  agree  that, 

471.  If  the  brain  be  acted  on,  the  effect  produced  by  it  on  the  mind 
will  depend  on  its  nature  and  condition. 

472.  Whether  its  nature,  as  it  regards  sensation,  differs  in  different 
persons,  cannot  be  ascertained  ;*  but  it  has  been  gifted  with  certain  pow- 
ers by  the  Creator,  which  it  cannot  transcend. 

573.  The  condition  of  the  brain  is  partly  natural  and  partly  artificial. 
One  person  is  so  constituted  that  slight  causes  produce  intense  sensa- 
tions, and  no  cultivation  will  entirely  change  this  inclination  of  his  sys- 
tem.     Another  person  is  so  constituted  that  the  most  powerful  causes 
may  act  on  the  brain,  and  yet  cause  but  slight  sensations. 

574.  An  artificial  state  or  condition  may  be  either  transient  or  per" 
manent.      Many  medicines  produce  a  transient  effect  on  the  brain  such 
that  causes  act  very  easily,  or  on  the  other  hand,  with  difficulty,  or  even 
such  a  state  of  the  brain  that  sensations  will  be  produced  merely  by  the 
state  of  the  brain.     The  effects  caused  by  the  use  of  alcoholics  till  deli- 
rium tremens  are  produced,  is  a  terrible  proof  of  this.     The  brain  is  in 
such  a  condition,  that  it  will  cause  sensations  of  sight  and  sound  never 
caused  by  aught  in  this  beautiful  world ;   and  the  pitiful  object  of  such 
visitations  believes  himself  surrounded  by  demons,  from  which  he  in  vain 
attempts  to  escape,  for  the  cause  of  his  sensations  is  in  his  poor  abused 
brain,  which  the  Creator  has  intended  shall  be  the  agent  in  the  produc- 
tion of  unspeakable  delight  to  those  who  observe  his  laws,  which  is  not 
to  obey,  but  to  seek  our  highest  good. 

575.  It  matters  not  to  the  mind,  whether  the  sensation  be  produced 
by  the  brain,  or  through  the  brain,  the  channel  through  which  the  mind 
is  acted  on  being  the  same,  every  sensation  seems  a  reality  ;  and  when, 
as  hereafter  seen,  the  brain  is  in  such  a  condition,  the  mind  cannot  use 
it  to  reason  with,  and  the  mind  is  left  unprotected  to  the  torment  of 
brain-produced  sensations. 

576.  If  the  brain  be  inflamed,  so  slight  a  cause  as  the  pulsation  of 
the  blood  will  produce  sensations,  perhaps  of  sight,  of  sound,  of  smell, 
taste,  &c. ;  while  the  use  of  opiates  can  produce  such  stupor,  viz.,  inabii- 

*  The  brain  is  now  spoken  of  merely  in  reference  to  sensations. 


208  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

ity  to  produce  sensations,  that  the  most  powerful  causes  cannot  produce 
sensations. 

577.  A  permanently  artificial  state  of  the  brain  is  caused  by  the  use 
of  medicines,  by  continued  diseases,  and  by  continued  habits  of  living. 
An  overloaded  stomach  for  a  single  time,  produces  an  obtuse  <=tate  of  the 
brain  for  a  short  while  only ;  but  constant  overfeeding  dulls  the  senses 
permanently ;   while  wholesome  food,  air,  drink,  clothing,  and  regular, 
reasonable,  common-sense  habits  of  every  kind,  will  tend  to  perfect*  the 
state  of  the  brain,  and  render  it  an  active  agent  in  the  production  of 
agreeable  sensations. 

578.  It  is  therefore  evident,  that  whoever  is  unhealthy,  or  uses  articles 
as  food  or  drink,  or  in  any  way  so  acts  upon  the  brain,  as  to  produce  an 
unhealthy  or  unnatural  state  of  the  brain,  cannot  form  a  good  judgment, 
as  the  sensations  which  will  be  produced  are  not  healthy  and  natural,  and 
his  mind  will  be  acted  upon  by  agreeable  or  disagreeable  sensations,  but 
not  such  as  would  be  produced  by  objects  acting  through  a  perfect  brain. 
And  upon  any  trial,  it  will  be  found  that  a  man's  judgment  will  be  influ- 
enced very  much  by  the  sensations  produced,  not  only  by  the  thing  under 
consideration,  but  by  any  thing. 

579.  It  will,  therefore,  be  exceedingly  difficult  to  find  persons  who 
will  think  alike  on  the  same  subjects,  or  any  person  who  will  be  uniform 
in  his  feelings  or  opinions ;  for  his  mind  has  such  a  changeable  brain 
and  nerves  through  which  to  receive  sensations,  that  if  itself  be  always 
the  same,  it  must  form  very  different  opinions  at  different  times,  the 
testimony  is  so  different  at  different  times.* 

580.  It  is  especially  worthy  of  notice,  that  a  person  is  under  obliga- 
tion not  to  unfit  his  brain  for  producing  natural  sensations,  by  the  *  use 
of  such  articles  as  poisonous  alcohol,  tobacco,  etc.,  or  by  any  such  course 
of  life  as  unfits  him  for  judging  correctly  of  himself  or   others,  and 
of  the  world.     To  illustrate ;  a  person  by  the  use  of  tobacco  produces 
such  an  effect  upon  his  brain  and  nerves,  that  he  cannot  form  a  correct 


*  It  will  be  found  that  people  form  favorable  opinions  of  almost 
any  thing  which  is  presented  to  them,  when  they  are  acted  upon  by 
causes  of  agreeable  sensations.  Hence  the  custom  of  "  feeding"  our  legis- 
lators when  a  request  is  to  be  made  of  them.  And  as  first  impressions 
are  so  strong  and  lasting  with  most  people,  it  is  always  preferable  to 
present  a  new  topic  before  the  mind,  in  connection  with  something 
which  with  certainty  will  produce  agreeable  sensations.  And  if  a  dis- 
agreeable thing  must  necessarily  be  brought  before  the  mind,  let  it  be 
combined  with  something  which  will  produce  agreeable  sensations. 


SEC.  5.]         THE  BRAIN  AS  AN  ORGAN  OF  SENSATION.  209 

judgment  of  how  offensive  his  breath  is  to  others,  who  certainly  have  a 
nght  to  receive  the  common  air,  pure  and  uncontaminated.  A  person 
who  has  used  alcoholic  beverages,  has  unfitted,  for  the  time,  his  brain 
for  producing  disgusting  sensations,  such  as  his  deportment  and  con- 
versation produce  through  a  brain  unclouded  by  the  effects  of  poisons. 
He  will  often  so  much  mistake,  as  to  think  himself  exceedingly  agree- 
able ;  indeed,  be  so  much  deceived  as  to  think  the  exhilaration  which  he 
has  produced,  gives  brilliancy  to  what  he  supposes  accomplishments,  but 
which  an  undeceived  mind  would  look  upon  as  awkward  at  best,  but 
exceedingly  clownish  when  exaggerated  by  dissipation. 

581.  The  second  duty  of  the  brain  is  to  cause  the  sensa- 
tions to  appear  to  be  at  the  commencement  of  the  nerve 
through  which  they  are  produced. 

If  a  nerve  be  pricked  in  the  finger,  the  sensation  appears  to  be  in 
the  finger,  and  we  say,  it  seems  to  us  that  the  finger  is  pained. 

582.  The  object  of  this  is  to  call   attention  to  the  part 
exposed  to  danger.' 

If  the  finger  be  injured,  it  is  necessary  to  call  attention  to  the  part 
injured,  that  the  cause  of  the  injury  may  be  removed. 

583.  If  the  disease  or  cause  producing  injury  be  not 
found  at  the  commencement  of  the  nerve,  it  must  be  in  the 
course  of  the  nerve,   between  its  commencement  and  the 
brain.  . 

If  the  elbow  be  struck,  two  sensations  are  produced,  one  of  acute 
pain,  which  appears  to  be  at  the  elbow  where  the  cause  is  acting,  and 
the  other  of  a  prickling  character,  appears  to  be  in  the  little  finger ;  but 
the  cause  of  the  sensation  is  not  there,  but  at  the  elbow  in  the  course  of 
the  nerve.  If  certain  diseases  affect  the  spinal  cord,  some  of  the  nerves 
composing  it  will  be  so  acted  upon  as  to  cause  sensations  like  the  creep- 
ing of  animals ;  these  sensations  will  appear  to  be  at  the  commencement 
of  the  nerves  through  which  they  were  produced.  A  person  frequently 
has  "  chills  run  over "  certain  parts  of  the  body,  owing  to  effects  pro- 
duced on  certain  nerves  in  some  part  of  their  course.  In  fever  and  ague 
the  nerves  in  some  part  of  their  course,  perhaps  the  spinal  cord,  are  so 
acted  on  as  to  be  in  the  same  state  as  if  their  commencing  points  were 
affected  by  cold  ;  the  person  feels  as  if  his  skin  were  cold,  and  goes  to 
the  fire  to  warm  the  nerves,  but  his  hopes  are  vain.  It  is  disease,  not 


210  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

any  want  of  heat,  that  causes  the  state  of  the  nerves  producing  the  sen- 
sations he  feels. 

584.  The  seat  of  disease  is  determined  in  these  cases,  by 
examining,  in  the  first  place,  the  parts  in  which  disease  ap- 
pears to  exist :  if  they  are  healthy,  it  must  exist  in  such  a 
part  as  to  affect  all  the  nerves  extending  from  the  parts  ap- 
parently affected,  to  the  brain ;  and  as  the  part  where  the 
nerves  from  these  parts  come  into  each  others5  vicinity,  is 
known,  the  disease  is  at  once  located. 

Hence  in  neuralgia,  when  the  pain  seems  to  be  produced,  now  here, 
now  there — "  darting  about " — it  would  be  natural  to  conclude,  that  the 
disease  existed  at  some  point  where  it  affected  all  the  nerves,  extending 
from  the  parts  where  the  pain  seemed  to  be  produced  and  the  brain.  If 
the  pain  be  confined  to  any  particular  part  of  the  body — as  the  face — the 
seat  of  the  disease  must  be  comparatively  small ;  while  if  the  pain  seems 
to  range  over  the  entire  body,  the  seat  of  the  disease  must  be  more  ex- 
tensive. The  same  comparative  course  would  be  pursued,  and  the  same 
comparative  judgment  formed,  if  the  disease  be  such  that  no  sensations 
are  caused  by  certain  parts  of  the  body ;  the  cause  of  the  paralysis  must 
be  looked  for  at  such  part  where  it  will  include  all  the  nerves  from  the 
paralyzed  part. 

585.  There  are  two  exceptions  to  the  proposition  of  paragraph  581 : 
1st,  some    sensations   appear   to  be   produced   at   the  commencement 
of  nerves  which  have  been  in  no  way  agents  in  producing  the  sensa- 
tions.    Thus  disease  of  the  liver  is  apt  to  cause  sensations  to  appear  to 
be  produced  under  the  shoulder.     In  "  hip  complaint,"  the  first  sensa- 
tions of  pain  seem  to  be  in  the  knee,  while  the  nerves  extending  from 
the  knee  to  the  brain,  as  far  as  we  know,  are  not  affected  in  any  way. 
Why  this  is  so,  is  not  known. 

586.  The  second  exception  is  in  case  of  many  sensations,  such  as 
hunger  and  thirst.     These  and  the  like,  do  not  appear  to  be  produced 
any  where  in  particular ;  nor  is  it  known  by  what  part  of  the  body  they 
are  caused.     Some  have  supposed  they  were  produced  by  the  stomach  ; 
and  a  variety  of  other  suppositions,  equally  groundless,  have  been  made. 
They  are  for  the  purpose  of  causing  us  to  eat,  drink,  &c.,  and  of  that 
general  character  having  reference  to  the  good  of  the  entire  body,  that 
there  is  no  necessity  for  their  being  produced,  or  seeming  to  be  produced, 
by  any  particular  part. 


SEC.  6.]  THE  MIND  IN  RESPECT  TO  SENSATION.  211 

587.  There  is  another  class  of  sensations  produced  by  the  action 
of  the  brain  upon  the  mind  when  we  think,  but  a  proper  place  for  dis- 
cussing these  briefly,  is  in  another  chapter. 


SEC.  6. — The  Mind  in  respect  to  Sensation. 

588.  What  office  the  mind  performs  in  the  production  of  sensations, 
is  uncertain.  Some  suppose  that  the  mind  itself,  in  itself,  is  capable 
of  producing  sensations  similar  to  those  of  sight,  &c.,  produced  ordi- 
narily by  the  action  of  the  nervous  system.  Some  suppose  that  the  mind 
is  capable  of  acting  upon  the  nervous  system,  so  as  to  produce  those 
states  which  cause  sensations  ;  but  that  by  itself,  it  cannot  cause  sensa- 
tions. Some  have  supposed  that  the  mind  was  of  different  qualities  in 
different  persons,  so  that  if  the  same  state  of  the  brain  should  be  brought 
to  act  on  the  different  minds,  similar  effects  would  not  be  produced  on 
account  of  the  different  constitution  of  the  minds.  Some  have  thought 
that  different  states  of  the  mind  were  produced  by  the  different  states 
of  the  brain ;  and  that  also,  these  different  states  of  the  mind  could  be  pro- 
duced without  the  agency  of  the  brain  ;  consequently  that  all  the  sensa- 
tions of  sight,  &c.?  could  be  produced  in  the  mind  of  the  person,  blind  not 
only,  but  wanting  the  nerves  of  sight.  All  these,  and  a  hundred  like 
questions,  I  readily  confess  my  inability  to  solve  ;  but  from  all  the  proofs 
afforded  by  physiology,  I  am  inclined  to  think  that, 

589.  Sensations  are  never  produced,  except  by  action 
of  the  brain  upon  the  mind ;  and  that  the  character  of  the 
sensation  depends  entirely  on  the  state  of  the  brain,  because, 

590.  1st,  I  cannot  find  any  good  proof  that  sensations  are  ever  pro- 
duced except  when  there  is  an  opportunity  for  the  action  of  the  brain 
upon  the  mind.     When  a  person  dreams,  there  is  not  only  an  opportu- 
nity for  the  brain  to  act,  but  late  suppers,  and  other  such  causes  as  tend 
to  produce  certain  states  of  the  brain,  are  the  most  frequent  causes  of 
dreams. 

591.  2d,  When  certain  states  of  the  brain  are  produced,  s«ch  that  it 
cannot  act  on  the  mind,  the  mind  does  not  realize  sensations.     The  brain 
has  frequently  by  accident  been  exposed,  so  that  it  could  be  pressed  ;  the 
instant  pressure  was  made,  sensation  was  suspended,  and  when  the  pres- 
eure  was  removed,  sensation  was  again  produced ;  so  perfect  would  be 


212  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

the  suspension,  that  if  every  thing  remained  in  the  same  place,  during  the 
pressure,  without  the  person's  anticipating  it,  he  would  neither  know  it 
had  been  made,  nor  suppose  any  time  had  elapsed,  but  as  if  nothing  had 
happened  continue  the  sentence  in  the  midst  of  which  he  was  inter- 
rupted. 

592.  3d.  The  sensation  produced,  is  always,  so  far  as  we  can  learn, 
in  accordance  with  the  state  of  the  brain  and  nervous  system.  If  the 
nerve  of  a  tooth  be  touched,  we  can  anticipate  what  sensation  will  be 
produced.  If  the  eye  be  inflamed  in  certain  parts,  we  can  anticipate 
that  a  little  light  will  produce  a  sensation  of  dazzling,  and  the  skilful  physi- 
cian, by  taking  into  consideration  the  condition  of  his  patient's  nervous 
system,  can  usually  judge  what  kind  and  degree  of  sensation  he  feels, 
If  the  eye,  nerve,  and  brain,  be  perfectly  healthy,  we  know  what  colors 
will  produce  agreeable  sensations.  The  world  over,  a  combination  of 
blue  and  orange  colors  are  pleasing,  so  are  red  and  green,  or  any  colors 
a  mixture  of  which  will  produce  white  light ;  blue  and  red,  red  and  yel- 
low, are  disagreeable  (Fig.  85).* 

Fig.  85. 


*  Those  colors  which  mingled  produce  white,  are  called  harmoni- 
ous, or  complimentary  when  spoken  of  in  reference  to  each  other. 
The  combinations  not  producing  white,  are  called  disharmonious.  In 
Fig.  85,  the  simple  colors  are  placed  at  the  angles  of  a  triangle,  in  a 
circle.  They  are  of  course  harmonious  and  complimentary  of  each  other. 
At  intermediate  points  of  the  circle  and  at  extremities  of  diameters  are 
placed  colors  formed  of  those  at  the  nearest  corners  of  the  triangle,  and  it 
will  be  seen  that  colors  at  the  extremities  of  diameters  are  harmonious  or 
complimentary' ;  so  will  be  all  shades  of  the  same  colors  which  would  be 
formed  at  the  extremities  of  any  diameters.  In  consideration  of  this 
Muller  remarks,  "  Women  of  good  taste,  when  they  have  a  single  pre- 
dominant color  in  their  dress,  select  a  dull  one ;  or  if  they  wear  pure 
colors,  combine  those  which  harmonize  from  being  complimentary  of  each 


SEC.  6.]  THE  MIND  IN  RESPECT  TO  SENSATION.  213 

593.  4th.  The  character  of  the  sensation  changes  too  easily  for  us 
to  suppose  that  it  depends  on  the  mind.  Various  articles  of  food  pro- 
duce a  high  relish  for  other  articles ;  a  "  taste"  is  soon  acquired  for  food 
at  first  "  very  disagreeable."  A  glass  of  wine  will  often  make  a  person 
pleased  with  the  effect  of  objects  otherwise  disliked;  a  thousand  other 
instances  could  be  suggested. 

594.  It  would  seem,  therefore,  as  the  tendency  of  objects 
to  produce  effects  is  uniform  and  invariable,  and  on  the  other 
side,  so  to  speak,  of  the  nervous  system,  the  character  cr 
nature  of  the  mind  uniform  and  invariable,  that  all  variation 
in  sensations  is  to  be  attributed  to  the  variable  character  or 


other ;  for  instance,  they  wear  a  red  shawl  over  a  green  dress,  combine 
lilac  with  yellow,  or  blue  with  orange.  How  beautiful  and  pleasing  to 
the  eye,  is  the  combination  of  a  golden  orange  color  with  blue  ;  for  in- 
stance, of  an  orange  fringe  with  a  blue  drapery,  while  the  dress  of  a  fe- 
male in  which  pure  yellow  were  combined  with  red,  or  yellow  with  blue, 
or  blue  with  red,  would  by  every  person  be  regarded  as  hideous  and  out 
of  taste.  Such  striking  combinations  of  disharmonic  colors  are  chosen 
only  for  national  signs  and  the  dress  of  soldiers.  The  disharmony  be- 
tween two  colors  may  however  be  removed  by  the  interposition  of  a  third 
color  which  is  the  harmonic  of  one  of  them,  and  is  indifferent  in  relation 
to  the  other,  as  in  red,  green  and  yellow  ;  blue,  orange  and  red,  &c. 
Painters,  either  intentionally  or  without  being  aware  of  it,  make  constant 
application  of  these  physiological  principles  ;  and  the  pleasing  effect  of 
colors  in  a  picture,  depends  on  the  skilful  combination  of  harmonic  colors. 
By  employing  principally  the  dull  gray  colors  the  danger  of  disharmonies 
is  avoided,  but  the  whole  charm  arising  from  the  harmonic  combination 
of  colors  is  renounced."  Thus  persons  may  dress  or  furnish  their  houses 
in  a  pleasing  manner  by  applying  physiological  principles  ;  but  in  dress, 
what  has  been  said  upon  the  reflection  of  light,  must  be  remembered  ; 
viz.,  that  light  from  the  dress  passes  to  the  complexion  and  is  reflected, 
mingled  with  any  other  light  reflected  from  the  face.  Some  articles  of 
dress  would  improve  the  complexion,  therefore,  and  if  at  the  same  time 
harmonious  in  colors,  very  pleasing  sensations  will  be  produced.  But 
the  greatest  care  will  be  requisite  in  arranging  bright  or  pure  colors 
either  by  natural  taste,  or  by  rule  ;  hence  it  is  safest  for  most  persons  to 
be  sure  and  never  offend  good  taste,  but  to  wear  unobtrusive  colors  and 
small  figures  and  furnish  their  apartments  in  a  similar  manner.  Yet  by 
study  a  person  can  improve  upon  this  plan  and  secure  much  admiration.* 

*  It  is  worthy  of  admiration  that  in  all  the  natural  objects,  among  millions  of  flow- 
ers of  every  hue  and  tint  of  color,  in  the  "  ever  changing  glories  of  the  sky,"  colors  in 
near  relation  to  each  other  are  always  harmonious.  Hence  why  flowers  and  imitations 
of  natural  flowers  are  ever  so  attractive  and  adorning  and  it  is  a  little  eineular  that 
"  flower  makers"  should  combine  flowers  and  colors  as  nature  never  does,  taking  paina 
to  avaid  a  perfect  model,  and  always  with  a  bad  effect. 


214  OEGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

state  of  the  organs  of  sense,  nerves  and  brain ;  to  wit,  as 
these  parts  are,  so  are  the  sensations. 

595.  The  duty  of  the  mind  seems  therefore,  in  respect  to 
sensations,  to  be  :  to  perceive  them,  to  judge  where  they  have 
been  produced,  and  to  be  pleased  with  them  if  their  causes 
are  productive  of  no  harm  to  the  body,  and  to  be  repugnant 
towards  all  which  are  produced  by  causes  acting  harmfully, 
to  remember  them,  to  compare  those  remembered  with  each 
other  and  with  new  ones,  and  thus  acquire  knowledge  of  the 
objects  which  surround  us  and  of  the  states  of  the  internal 
parts  of  the  body. 

596.  Perceiving  sensations.     Nothing  is  known  of  the  manner  in 
which  sensations  are  perceived,  in  other  words,  how  the  brain  acts  upon 
the  mind.     It  may  be  curious  to  ask  if  the  mind  occupy  much  space  in 
the  brain,  or  if  all  the  nerves  of  sensation  terminate  almost  at  the  same 
point?  No  reply  can  be  given.  The  only  light  that  is  shed  upon  the  subject, 
is  obtained  from  this  ;  that  nerves  from  different  organs  of  sense,  do  not 
seem  to  pass  towards  the  same  identical  point  of  the  brain.*  The  nerve  of 
sight  does  not  follow  the  course  of  the  olfactory  nerve,  though  they  are 
very  near  each  other  at  one  point.     The  nerve  of  sight  takes  a  very  cir- 
cuitous route  to  where  it  appears  to  terminate,  as  if  there  were  a  necessity 
in  the  fulfilment  of  its  duties  that  it  should  visit  certain  parts  of  the  brain. 
But  where  it  appears  to  terminate  may  not  be  its  stopping  place.     Much 
might  be  written  therefore,  and  yet  be  but  little,  as  it  would  be  so  unsat- 
isfactory. 

597.  The  mind  has  control  over  its  powers  of  perceiving  sensations. 
As  the  expression  is,  "  it  can  give  attention "  to  sensations,  or  divert 
its  attention.     How  this  is  done  is  not  known.     Whether  it  removes 
itself  from  the  part  of  the  brain  through  which  sensations  are  produced, 


*  If  metaphysicians  find  any  fault  (which  they  reasonably  may)  with 
language  used  in  a  physiological  discussion  of  mental  operations,  they 
are  desired  to  remember,  that  it  is  the  wish  not  to  be  considered  as 
entering  on  their  department  of  learning  at  all.  What  is  said  is  merely 
in  connection  with  physiology,  and  to  convey  clear  ideas  on  that  subject ; 
metaphysical  interpretation  is  not,  therefore,  ever  to  be  given  to  terms 
used,  but  a  physiological  sense  merely.  Any  point  in  metaphysics  will 
be  instantly  yielded,  as  belonging  to  a  subject  upon  which  men  more 
learned  in  that  department,  are  better  qualified  to  express  an  opinion. 


SEC.  6.]  THE  MIND  IN  RESPECT  TO  SENSATION.  215 

or  whether  it  stills  the  action  of  the  brain,  is  all  unknown.  The  ex- 
ercise of  this  power  of  attention  affects  the  intensity  of  sensations  in  a 
remarkable  degree.  If  attention  be  given  to  the  sensations  produced  by 
food,  they  will  be  very  much  heightened  thereby,  as  hereafter  seen ; 
facilitating  the  process  of  digestion,  if  the  food  be  wholesome.  But  if 
the  attention  of  the  mind  be  absorbed  with  business  etc.,  food  will  be 
swallowed  without  relish,  and  very  soon  such  a  course  will  be  followed 
by  dyspepsy.  A  person  may  ride  through  the  pleasantest  section  of 
country  and  appreciate  none  of  its  charms,  because  his  mind  gives  no 
attention  to  causes  of  sight  and  sound.  To  one  person  there  are  "  ser- 
mons in  stones,  books  in  brooks  ;"  another  person  looks  upon  the  beau- 
tiful flower  and  no  admiration  is  awakened,  for  his  mind  heeds  not  the 
sensations  it  was  made  to  produce. 

598.  The  attention  of  the  mind  being  engrossed  with  the  importance 
of  staying  the  ravages  of  fire,  or  with  the  strife  of  battle,  a  person  feels 
not  a  wound,  or  the  most  exhausting  fatigue.     On  the  other  hand,  the 
attention  of  the  mind  will  cause  the  slightest  sensations  to  appear  in- 
supportable.    He  who  gives  attention  to  every  ache  and  ail,  will  soon 
appear  to  himself  to  be  the  most  afflicted  of  the  human  family,  and 
indeed,  he  will  suffer  more  than  those  who  are  acted  upon  by  the  most 
powerful  causes  of  painful  sensations.     To  nurse  every  pain  of  a  child, 
caused  by  cut  or  bruise,  etc.,  is  to  make  it  suffer  on  the  slightest  occa- 
sion ;  while  to  call  off  its  attention  and  make  it  "  forget "  the  hurt,  is  to 
teach  it  to  be  manly,  and  use  the  true  means  of  relieving  unavoidable 
misfortunes  of  their  intensity. 

599.  Judgment  of  where  the  sensations  have  been  produced.     How 
this  is  arrived  at  by  the  mind  is  not,  of  course,  known.    Some  sensations 
are  general,  but  most  seem  to  be  produced  at  the  commencement  of  the 
nerve  through  which  they  have  been  produced.     The  mind  is  liable, 
therefore,  to  many  errors  in  respect  to  the  state  of  the  body.     Sometimes 
diseases  seem  to  be  at  the  commencement  of  nerves,  not,  as  far  as  can  be 
judged,  being  at  all  concerned  in  the  production  of  the  sensation.     Some 
suppose  the  state  of  nerve  necessary  to  produce  a  sensation,  is  caused 
in  the  nerve  of  the  unaffected  part  by  the  nerve  of  the  affected  part, 
which  passes  near  to  it,  but  this  is  uncertain.     Disease,  and  various 
causes,  by  acting  on  the  nerve  in  some  part  of  its  course,  as  has  been 
shown,  would  lead  the  mind  astray  in  the  formation  of  its  opinion.    The 
most  tormenting  itchings,  and  terrible  pains,  are  thus  very  frequently 
thought  to  be  produced  by  the  state  of  a  part  which,  in  fact,  is  quite 
healthy,  and  many  applications  will  be  made  without  avail.     The  power 


216  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

of  causes  producing  sensation,  is  judged  by  the  intensity  of  sensation ; 
but  this  depends  not  only  on  a  cause,  but  on  the  state  of  the  nervous 
system  through  which  the  cause  acts.  A  slight  cause,  therefore,  in  one 
person  produces  acute  pain,  and  from  similar  pain  in  another,  it  might 
be  argued  that  the  cause  was  slight,  when,  in  fact,  it  was  not  so.  In 
the  first  case  nothing  being  done,  the  person  would  recover  perhaps  ;  in 
the  last  he  would  die.  Thus  is  evidently  seen  the  importance  of  edu- 
cated, experienced  skill. 

600.  In  a  similar  manner  is  the  mind  liable  to  misjudge  of  causes 
surrounding  us.     There  being  so  many  causes  beside  surrounding  objects 
which  modify  the  sensations  upon  which  the  mind  bases  its  judgment ; 
for  instance,  a  rush  of  blood  through  or  across  inflamed  nerves  causes 
sensations  which  make  the  mind  believe  that  a  carriage  is  rumbling,  a 
bell  ringing,  etc.     So  an  "excited"  state  of  the  nervous  system  will 
cause  sensations  of  sight  entirely  unworthy  of  confidence. 

601.  Production  of  pleasing  and  disagreeable   sensations.      The 
mind  is  so  made  as  to  be  usually  pleased  with  the  sensations  caused  by 
harmless  objects  or  a  healthy  state  of  the  system,  and  disagreeably  af- 
fected by  those  of  harmful  objects  or  states  of  the  system.     But  there  are 
exceptions:  the  exhilarating  effects  of  alcoholics,  and  the  "reconciling" 
effects  of  tobacco,  are  seductive  to  man,  but  refused  by  animals.     Why 
this  is  so  is  evident,  if  the  destiny  of  man  be  considered.     He  has  not 
been  designed  to  occupy  so  narrow  a  portion  of  the  world  as  any  other 
species  of  animal.      The  whole  earth  is  his  inheritance  ;    his  hand  com- 
bines the  weapons  of  every  other  animal ;  his  reason  more  than  compensates 
for  the  instinct  of  the  geometrical  bee  or  the  architectural  beaver,  and 
the  range  of  his  tastes  includes  every  variety  of  pleasure  that  air,  earth, 
and  water  are  capable  of  producing  through  nerves  and  brain.     To  think, 
however,  is  the  chief  duty  of  man,  as  well  as  the  source  of  his  highest 
pleasure.     To  preserve  himself  from  danger,  in  many  cases,  nature  there- 
fore  has  made  it  necessary  for  him  to  acquire  knowledge  and  apply  it, 
of  which  necessity  she  has  deprived  animals,  supplanting  it  by  unmerit- 
ing  instinct,  which  always  compels  the  animal  to  act  for  its  good ;   but 
man  can  use  his  powers  or  not,  and  for  his  good  or  harm,  as  he  chooses. 
His  instincts  warn  him,  therefore,  only  of  dangers  of  which  the  applica- 
tion of  his  cultivated  mind  could  not  warn  him,  and   this  they  do  most 
perfectly. 

602.  Memory  of  sensations.     This  is  an  exceedingly  important  duty 
of  the  mind.     It  would  seem  that  the  mind  performs  this  act  unassisted 
by  the  brain,  since,  as  will  hereafter  be  shown,  the  brain  is  continually 


SEC.  6.]  THE  MIND  IN  RESPECT  TO  SENSATION.  217 

undergoing  changes  in  all  its  parts,  so  that  no  portion  of  it  remains  much 
length  of  time  in  one  position.  Some  suppose,  that  when  the  mind  would 
remember  a  sensation,  it  so  acts  on  the  brain  as  to  produce  a  similar  state 
as  that  which  previously  existed  when  the  desirable  sensation  was  per- 
ceived, and  that  when  the  state  of  the  brain  cannot  thus  be  reproduced 
by  the  mind,  the  sensation  cannot  be  recalled.  Others  suppose  that  an 
effect  once  made  upon  the  mind  by  the  brain,  can  be  recalled  by  the  mind 
without  the  assistance  of  the  brain.  It  matters  not — sensations  are  re- 
membered, and  by  that  means, 

603.  Sensations  can  be  compared.     By  this  important  process  the 
mind  stores  itself  with  useful  ideas,  and  knows  the  cause  of  sensations. 
For  instance,  if  a  pound  weight  be  taken  in  the  hand,  and  the  sensation 
be  remembered,  the  next  time  a  weight  be  taken  in  the  hand  that  upon 
comparison  produces  a  similar  sensation,  it  is  considered  to  weigh  a  pound. 
If  sugar  has  caused  its  sensation,  which  is  remembered,  sugar  will  be 
thought  the  cause  of  any  similar  sensation,  and  so  of  other  things,  and 
also  of  the  internal  states  of  the  system ;  for  instance,  if  a  person  have 
suffered   any  kind  of  pain  in  any  part  of  the  body,  and  feels  the  like 
again,  the  cause  having  been  learned  or  told  him  in  the  first  instance,  he 
will  think  it  exists  again.     Thus  from  the  kind  of  pain  and  location  of  it, 
the  physician  judges  very  much  in  respect  to  disease. 

604.  But  the  mind  is  very  liable  to  fall  into  errors.     Causes  produc- 
ing sensations  are  so  numerous,  that  it  requires  a  very  long  time  to  expe- 
rience in  regard  to  them  all.      Many  produce  similar  sensations,  fcnd 
mistakes  may  be  made,  like  that  of  the  negroes  of  the  West  Indies  em- 
ployed to  unload  the  first  cargo  of  ice  ever  carried  to  those  places.    They 
threw  down  the  first  lumps,  declaring  they  were  burned.      Such  sensa- 
tions they  had  never  felt,  except  produced  by  heat.     They  knew  not  that 
intense  cold  produces  similar  sensations.     Again,  objects  with  which  we 
are  acquainted  produce  sensations  so  similar,  that  much  skill  and  experi- 
ence is  required  that  an  accurate  comparison  may  be  made.     Again,  the 
sensations  produced  by  a  cause,  and  the  comparisons  made,  depend  much 
upon  what  causes  have  preceded.      The  taste  is  altered  by  various  arti- 
cles, as  already  shown.      If  the  eye  have  been  fixed  on  a  bright  red 
object,  and  then  turned  to  a  white  one,  it  will  appear  green  ;  for  the  effect 
of  the  red  has  so  fatigued  the  nerves,  if  the  expression  may  be  used,  that 
the  red  light  from  the  white  object  produces  no  effect,  and  the  blue  and 
yellow  acting  without  the  red,  produce  the  effect  of  green.      If  heavy 
weights  have  been  held,  a  pound  weight  will  seem  very  light.      So  also 
different  states  of  the  same  or  different  parts  of  the  body  produce  similar 

10 


218  ORGANS  OF  SENSATION  OR  PEELING.  [CHAP.  II. 

sensations ;  and  also  as  tne  sensations  produced  by  surrounding  objects 
and  the  states  of  the  body  depend  on  the  condition  of  the  nervous  system, 
it  is  evident  that  great  experience  is  necessary,  as  well  as  a  very  retentive 
memory  of  sensations,  and  an  accurate  judgment  to  compare,  that  the 
mind  may  arrive  at  correct  conclusions  in  respect  to  the  causes  producing 
the  sensations  it  perceives.  The  mind  obtains  assistance  also  in  deter- 
mining the  character  of  objects,  by  causing  any  object  about  which  there 
is  doubt,  to  produce  more  than  one  kind  of  sensation  ;  for  if  different  ob- 
jects produce  similar  sensations  of  one  kind,  they  will  produce  different 
sensations  of  some  kind.  It  is  of  much  importance,  therefore,  to  know 
what  similar  and  what  dissimilar  sensations  different  objects,  especially 
different  diseases,  produce.  For  if  similar  sensations  of  two  or  three 
different  kinds  are  produced,  we  are  apt  too  hastily  to  think  that  the 
causes  are  similar.  A  dropsy,  for  instance,  may  exist,  and  one  in- 
experienced would,  perhaps,  think  there  is  one  cause  and  one  cure ; 
but  greater  skill  would  teach  that  dropsy  is  an  effect  produced  by  many 
different  causes,  and  other  signs  would  be  looked  for,  till  by  them  the 
common  cause  of  them  and  the  dropsy  would  be  found.* 


SECTION  7. — Concluding  Remarks  on  the  Organs  of  Sensation. 

9  605.  So  little  is  known  of  the  precise  manner  in  which  any  organ 
of  sensation  performs  its  duty,  that  it  is  impossible  to  make  any  very  par- 
ticular inferences  in  respect  to  the  particular  mode  of  managing  the  va- 
rious parts  of  them.  From  the  powerful  sensations  produced  by  the 
minute  particles  of  odoriferous  substances,  too  subtle  to  be  appreciated 
by  other  se.ises  than  that  of  smell ;  from  the  ready  action  of  the  feeblest 
causes  of  sound,  which  can  only  be  produced  by  a  change  in  the  state 
of  the  nerve  ;  from  the  powerful  action  of  only  a  single  grain  of  morphin^  or 
a  drop  of  prussic  acid,  which  will  lock  the  nervous  system  in  the  soundest 
slumbers — many  times  the  sleep  of  death — it  would  be  expected  that, 

606.  What  would  usually  be  called  insignificant  causes 
will  be  sufficient  to  produce  disease  of  the  nervous  system, 

*  Here  the  folly  is  seen  of  "  doctoring"  signs  or  symptoms,  or  ad- 
ministering remedies  without  great  knowledge,  the  result  of  study  and 
experience,  and  especially  without  a  knowledge  of  the  cause  of  the 
•ymptoms  exhibited. 


SEC.  7.]  CONCLUDING  REMARKS.  219 

causing  dreadful  suffering  and  most  tedious  in  its  duration  ; 
that  the  suffering  might  commence  suddenly  and  terminate 
as  quickly ;  that  as  the  slightest  causes  may  bring  it  on,  so 
the  slightest  causes  may  remove  it ;  that,  if  the  state  of  the 
nervous  system  be  changed  by  any  cause,  there  will  be  a 
change  in  the  sensations  produced  by  the  disease,  perhaps 
for  the  better,  perhaps  for  the  worse ;  and  from  what  has 
heretofore  been  said,  it  would  be  expected  that  sometimes 
one  thing,  sometimes  another,  would  change  the  state  of  the 
nerve,  by  which  painful  sensations  are  caused.  It  is  also  in 
accordance  with  common  sense,  that  while  an  endeavor  is  made 
to  change  the  state  of  the  nerve  causing  pain,  ALL  CAUSES 

TENDING  TO  PRODUCE  SUCH  A  STATE  MUST  BE  SEDULOUSLY 
AVOIDED. 

For  instance,  it  is  useless  to  call  on  the  doctor  to  cure  neuralgia, 
while  a  person  is  continually  exposed  to  take  cold,  etc. 

607.  It  is  also  found  that  pain,  by  the  effect  produced  on  the  good 
nature  of  a  person,  and  by  the  bad  effect  produced  upon  the  nervous 
system,  is  one  of  the  most  powerful  causes  for  deranging  the  action  of 
all  parts  of  the  body,  and  wearing  out  life. 

608.  If  any  state  of  the  nerves  producing  pain  can  be 
changed  without  doing  decided  injury,  it  should  be  done ; 
not  more  for  the  purpose  of  preventing  pain,  than  for  pre- 
venting the  farther  progress  of  disease. 

The  usefulness  of  this  principle  is  shown  by  the  great  reputation 
which  some  physicians  have  acquired  almost  solely  by  the  use  of  opium 
and  its  compounds,  and  of  other  narcotics  (inducing  sleep) .  These  articles 
are  indeed  great  blessings,  if  used  judiciously,  but  productive  of  eqnaj 
harm  if  improperly  used. 

609.  If  the  skin  be  exposed  to  the  cold,  and  the  blood  thus  driven 
from  the  nerves  in  the  skin,  the  sensations  produced  through  the  skin 
are  correspondingly  blunted.  Thus,  if  the  skin  may  be  taken  as  a  crite- 
rion, and  also,  from  the  fact  that  the  wants  of  all  parts  of  the  body  are 
supplied  from  the  blood;  it  may  be  inferred, 

610.  A  free  supply  of  pure  blood  is  requisite  that  the 
organs  of  sensation  may  fulfil  their  duties. 


220  ORGANS  OF  SENSATION  OR  FEELING.  [CHAP.  II. 

This  is  obtained  by  the  use  of  proper  food,  drink,  air,  and  all  the 
means  hereafter  shown  to  produce  pure  blood  ;  and  by  muscular  exercise, 
and  rubbing  the  system,  which  sends  the  blood  more  rapidly  through 
every  part  of  the  body,  by  proper  clothes,  etc.  And  if  the  exercise  of  the 
eye  may  be  taken  as  a  criterion, 

611.  Exercise  of  the  organs  of  sensation  causes  a  brisker 
flow  of  blood  through  them. 

The  eyes  of  the  student  frequently  afford  evidence  that  exercise 
increases  the  quantity  of  blood  passing  through  an  organ  of  sensation. 
Some  suppose  that  exercise  is  useful  only  by  causing  the  mind  to  give 
stricter  attention  to  the  sensations  produced ;  but  while  it  may  be  allowed 
that  attention  is  all  that  is  necessary  in  many  instances,  yet  it  is  also 
certain  that  the  sailor,  by  the  exercise  of  his  eye,  not  only  concentrates 
his  attention,  but  perfects  his  power  of  adapting  the  eye  for  long  sights ; 
while  by  exercise,  the  watchmaker  gains  the  power  of  adapting  the  eye 
to  near  objects.* 

612.  Proper  exercise  of  the  organs  of  sensation  improves 
their  physical  condition  and  powers. 

In  what  way  is  not  certain,  as  it  is  not  known  which  part  is  improved 
when  vivid  sensations  are  produced.  Without  doubt  the  power  of  giving 
attention  is  increased,  and  considering  things  hereafter  to  be  shown,  it  is 
probable  that  the  constituents  of  the  organs  of  sensation  undergo  changes 
in  the  fulfilment  of  their  duty,  which  changes  are  made  more  rapid  by 
exercise,  causing  the  increased  flow  of  blood  necessary  to  effect  the 
change,t  and  as  the  parts  undergo  their  changes,  they  become  adapted 


*  When  the  eye  turns  in  (is  cross-eyed)  from  want  of  power  of 
adaptation,  which  is  a  frequent  case,  it  can  be  trained  to  adapt  itself  by 
having  the  other  eye  covered  for  a  short  time  together,  but  very  fre- 
quently, and  then  using  the  ill  adapted  eye  in  looking  at  distant  or  near 
objects,  as  the  case  may  require.  In  some  cases  the  eyes  alternately 
turn  in,  because  one  can  adapt  itself  to  near,  while  the  other  can  only 
adapt  itself  to  distant  objects.  In  this  case  the  eyes  must  be  alternately 
covered  and  exercised  in  those  ways  in  which  they  ordinarily  fail. 
Nothing  of  tin's  kind  must  be  expected  to  succeed  except  with  months 
of  practice,  resolutely  persevered  in  every  day. 

t  When  an  eye  is  found  to  be  weak,  on  which  account  it  turns,  it 
may  many  times  be  strengthened  by  a  proper  course  of  exercise,  the  other 
eye  being  covered,  but  great  care  must  be  taken  not  to  use  the  feeble  eye 
too  long  at  one  time. 


SEC.  7.]  CONCLUDING  REMARKS.  221 

to  the  requirements  made  upon  them,  as  it  is  a  universal  rule  of  nature 
to  adapt  a  part  as  far  as  possible  to  fulfil  the  duty  required  of  it. 

613.  Whatever  may  be  the  particular  cause,  there  is  no 
doubt  that  exercise  renders  the  sense  of  touch  more  delicate, 
the  sense  of  taste  more   refined,  the  sense    of  smell  more 
acute,  the  sense  of  hearing  more  exquisite,  the  sense    of 
sight  more  perfect,  and  the  muscular  sense  more  accurate. 

614.  Over  exercise  enfeebles  the  organs  of  sensation. 

There  is,  however,  little  danger  of  over-exercise  of  any  organs  except 
those  of  sight.  Inhalation  of  intensely  acting  odors,  such  as  smelling-salts, 
etc.,  have  in  some  cases  much  injured  the  sense  of  smell,  while  strong 
spices,  etc.,  act  as  injuriously  upon  the  sense  of  taste. 

615.  The  remedy  for  over-exercise  is  rest,  entire,  and 
prolonged.* 

616.  Thus  is  concluded  the  chapter  on  sensations,  the 
contents  of  which,  may  not  "have  been  easy  to  understand 
without  some  study  and  thought ;  but  the  principles  herein 
developed  it  is  hoped  will  induce  the  reader  to  cultivate  to 
the  full,  his  powers  of  rationally  enjoying  this  world,  and  he 
will  exclaim  with  Campbell  the  poet  in  a  letter  to  a  friend, 
"  What  adorable  beauties  of  God's  and  nature's  bounties  we 
live  in  without  knowing." 

*  If  an  eye  be  weak,  and  turn  because  it  requires  rest,  this  should 
be  allowed  by  covering  it  for  a  long  while,  after  which  it  is  to  be  grad- 
ually strengthened  by  exercise. 


CHAPTER  IIL 

OKGANS   WITH   WHICH   TO   THINK. 

General  Observations. 

617.  1st.  Facts  already  advanced  prove  that  from  the  brain  influences 
are  exerted  upon  all  parts  of  the  body,  and  that  from   all  parts  of  the 
body  influences  are  exerted  through  the  brain  upon  the  mind,  producing 
sensations.    These  things  prove  that  the  mind  is  enthroned  in  the  brain  as 
a  political  capital,  from  which  centre,  through  the  nerves  as  avenues   of 
communication,  it  can  issue  its  mandates  to  every  part  of  its  corporeal 
kingdom,  and  from  every  part  of  it  receive  by  nerves,  continual  reports 
of  its  condition,  welfare,  and  wants.     Hence  it  would  be  necessary  that 
the  same  centre,  the  brain,  should  furnish  the  mind  with  the  apparatus 
necessary  for  thinking,  if  any  be  required. 

618.  2d.  When  engaged  in  thinking  a  person  experiences  a  sensation 
distinct  and  perfect  as  any  produced  through  the  ear  or  eye  ;  the  location 
at  which  it  is  produced,  appears  as  decided  as  in  case  of  sensations  of 
sound,  and  more  so  than  in  case  of  the  general  sensations  of  thirst,  hun- 
ger, &c.     Intense  thought  will  call  attention  to  the  front  part  of  the 
head,  as  if  the  acting  cause  of  thought  were  there.     If  the  hand  be  ap- 
plied to  the  forehead  it  will  feel  hot,  and  the  application  of  a  cold  cloth 
will  give  immediate  relief;  the  thoughts,  from  being  confused  and  vexing 
will  become  clear  and  pleasure-giving.      When  a  new  idea  has  been 
gained  not  only  is  there  a  feeling  that  knowledge  has  been  acquired,  and 
pleasure  thereat,  but  also  a  sensation  of  a  more  physical  character,  so  to 
epeak,  in  a  certain  sense  like  the  sensations  produced  through  the  ear, 
eye,  &c.     So  when  memory  is  exercised  or  judgment  formed,  a  sensa- 
tion is  felt,  feeble  or  intense,  of  a  pleasurable  or  unpleasant  character, 
in  the  same  manner  as  sensations  treated  upon  in  the  previous  chapter". 
A  sensation  of  this  character  is  called  consciousness    (physiologically 
speaking) .     Another  reason  why  consciousness  may  be  considered  as  a 


GENERAL  OBSERVATIONS.  223 

sensation  produced  by  the  action  of  the  brain  upon  the  mind  is,  that  con- 
sciousness ceases  the  instant  the  action  of  the  brain  ceases,  as  found  in 
cases  where  the  brain  is  or  can  be  pressed,  by  which  unconsciousness 
even  of  passing  time  is  produced.  Fits  of  apoplexy,  "  fainting  away," 
and  even  profound  sleep,  produce  a  similar  unconsciousness  even  of  ex- 
istence, for  the  brain  cannot  then  produce  sensations. 

619.  3d.  If  the  brain  be  slightly  inflamed,  not  only  are  sensations  of 
sound,  sight,  &c.,  readily  produced,  but  the  thoughts  spring  up  to  the 
mind  with  facility  and  succeed  each  other  in  a  very  rapid  manner,  while 
if  the  state  of  the  brain  be  such  that  sensations  of  feeling,  &c.,  are  pro- 
duced with  difficulty,  the  intensity  of  a  person's  thoughts,  as  well  as  their 
activity,  is  slight ;  thus  showing  that  the  character  of  a  person's  thinking 
powers  can  be  determined,  in  a  general  manner  at  least,  by  the  condi- 
tion of  the  brain. 

620.  4th.  It  has  been  often  noticed  by  the  student,  that  the  head  be- 
comes hot  and  the  feet  cold  when  engaged  in  intense  study.     Nothing 
is  more  common  than  to  hear  professional  and  indoor  business  men  com- 
plain of"  cold  feet,"  no  matter  how  warm  the  apartment  is  kept.     Why 
is  this,  except  that  the  activity  of  the  brain  necessary  when  thinking  is 
done,  requires  an  increased  supply  of  blood  1 

621.  5th.  Two  persons  may  hear  at  the  same  time,  of  the  death  of 
some  dear  friend  of  one  of  them  ;  the  voice  of  him  who  tells  the  tidings 
falls  on  the  ear  of  each  alike,  the  same  effect  is  produced  on  the  nerves 
of  hearing  in  each  case,  and  they  produce  the  same  effect  on  the  brain, 
and  the  physical  brain  produces  the  same  effect  on  the  mind.     But  the 
eyes  of  one  remain  dry,  while  tears  gush  from  those  of  the  other.     Why 
the  difference,  except  that  the  emotions  of  one  mind  act  upon  the  brain 
with  which  it  is  connected  and  through  nerves  upon  the  tear  apparatus  ? 
The  cheeks  redden  and  the  limbs  quiver  with  anger,  rage  will  even 
gnash  the  teeth,  while  smiles  are  indicative  of  gentle  feelings,  the  down- 
cast eyes  of  reserve,  nor  can  the  beautiful  blush  of  modesty  be  ever  seen 
on  the  face  where  haughtiness  rules  the  mind.     But  when  by  disease  or 
accident  the  nerves  connecting  between  the  brain  and  body  are  unfitted 
for  use,  an  unmeaning  stolidity  stares  from  the  expressionless  face. 

622.  6th.  In  the  morning,  the  heated  brain  of  the  evening  previous 
has  become  cool,  and  after  a  bath  of  cold  water  upon  the  head,  feels 
ready  for  action,  and  in  a  corresponding  manner  the  composed  thoughts 
of  the  evening  become  regular,  and  thinking  becomes  a  pleasure  ;  the  bu- 
siness man  gives  his  attention  to  his  business,  the  farmer  to  his  labors, 
the  student  to  his  studies,  and  all  with  delight.     So  during  the  day,  if 


224  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

the  mind  become  confused,  muscular  exercise,  a  walk,  a  ride,  or  aught 
else  which  gives  repose  to  the  tasked  brain,  will  produce  in  a  short  time 
regular  action  of  the  mind. 

623.  7th.  There  is  a  large  amount  of  nervous  substance  forming  a 
great  part  of  the  brain  for  which  thef'e  seems  to  be  no  use,  except  the 
mind  make  use  of  it  in  its  thinking  operations.  Other  arguments  might 
be  advanced,  but  these  are  sufficient  to  prove,  it  would  seem,  that 

624.  There  are  two  requirements  for  thinking :  1st,  a 
mind,  the  efficient  cause  of  thinking ;  2d,  a  brain,  with  which 
to  think. 


SECTION  1. — The  Brain. 

625.  How  the  mind  acts  upon  the  brain,  or  the  brain  upon  the  mind, 
in  the  production  of  thought,  is  not  known,  and  most  of  the  curious 
questions  which  might  be  asked  in  reference  to  the  matters  under  con- 
sideration can  only  be  answered  by  supposition,  supported  sometimes  by 
very  gcod  arguments,  but  usually  only  by  probabilities.  We  may  first, 
therefore,  notice  facts,  and  secondly,  follow  them  with  inferences. 

626.  a.  The  brain  is  composed  of  many  parts,  differing 
in  color,  structure,  composition,  form,  position,  relation,  and 
mode  of  connection  with  other  parts,  and  in  respect  to  the 
quantity  of  blood  received.      The  difference  in  any  of  these 
respects  is  not,  however,  very  great. 

b.  The  mind,  through  the  brain,  has  different  duties  to 
perform.     It  must  receive  sensations,  it  must  exert  influences, 
it  must  have  thoughts,  emotions,  &c. 

c.  When  one  kind  of  intellectual  pursuit  has  caused  fa- 
tigue, attention  can  be  given  to  another  with  nearly  o^  quite 
the  same  efficiency  as  if  no  fatigue  had  been  felt. 

627.  From  these  facts  it  is  inferred,  that  different  parts  of  the  brain 
are  used  by"  the  mind  in  fulfilling  its  various  duties.     To  this  it  may  be 
objected,  that  disease  of  any  part  does  not  always  produce  like  results. 
Sometimes  no  appreciable    results  are  produced  by  extensive  disease. 
Sir  Charles  Bell  states  that  he  has  seen  every  part  of  the  brain  except 


SEC.   1.]  THE  BRAIN.  225 

the  gray  part  extensively  diseased,  and  yet  the  duties  of  the  mind  well 
performed  ;  while  others  have  seen  the  gray  part  as  much  affected,  with- 
out producing  any  apparent  influence  on  the  accomplishment  of  the  men- 
tal duties.*  Large  portions  of  certain  parts  of  the  brain  may  be  lost,  by 
accident,  without  producing  any  apparent  effect  on  the  mental  operations. 
Such  facts  are  against  almost  any  inference  that  may  be  made  in  respect 
to  the  action  of  the  mind  and  brain  upon  each  other.t 

*  By  some,  it  has  not  only  been  inferred  that  the  brain  consists  of 
parts,  but  that  the  situation  of  these  parts  has  been  determined  ;  for  in- 
stance, that  the  front  parts  of  the  brain  are  the  organs  used  in  the  intel- 
lectual operations  of  the  mind.  Thesq  grand  divisions  have  again  been 
divided,  by  some,  into  a  small  number,  by  others,  into  a  multitude  of 
parts.  One  step  further  has  been  taken,  and  it  has  been  inferred  by 
some,  that  the  larger  these  parts  or  organs,  used  by  the  mind,  the  more 
efficiently,  other  things  being  equal,  can  its  duties  be  performed.  Still 
another  step  being  made,  it  has  been  inferred  that  the  size  of  these  parts 
or  organs  could  be  determined  by  examining  the  head  externally,  and 
thereby  the  capacities  of  a  person  determined,  other  things  being  equal. 
Whether  this  be  so,  any  person,  it  would  seem,  could  satisfy  himself  by 
making  a  few  experimental  examinations,  and  especially  by  examining 
and  comparing  the  skulls  of  different  skeletons,  and  noticing  if  there  be 
such  uniformity  in  their  thickness  in  corresponding  parts  as  to  warrant  the 
inference  that  the  size  of  the  different  parts  of  the  brain  could  be  determin- 
ed by  an  examination  of  the  head  externally,  even  if  it  were  allowed  that 
the  brain  was  composed  of  a  congeries  of  organs,  all  coming  to  the  surface 
of  the  brain,  and  that  the  larger  any  part  of  the  brain,  other  things  being 
equal,  the  more  effectual  the  operations  of  the  mind  through  it.  He 
might  then  examine  and  compare  brains  of  different  heads,  to  learn  if  the 
apparent  enlargement  of  any  part  of  the  brain  might  not  be  produced  by 
the  enlargement  of  some  other  part  crowding  upon  it,  so  to  speak,  and 
causing-  it  to  be  prominent ;  for  there  will  be  found  many  parts  in  the 
brain  \\hich  do  not  come  to  the  surface,  but  are  buried  deeply  below  the 
parts  forming  the  surface.  He  may  notice,  likewise,  that  many  parts  of 
the  brain  having  the  same  appearance  as  those  directly  within  the  skull, 
are  found  at  the  surface  of  the  brain,  where  the  falx  (Fig.  47)  separates 
one  half  the  brain  from  the  other.  He  might  ask  if  these  parts  do  not 
perform  important  duties  for  the  mind,  and  if  there  be  any  way  of  de- 
termining what,  or  how  much  effect,  the  action  or  size  of  those  parts 
of  the  brain  would  have  upon  the  character  and  capacities  of  a  person. 
Many  similar  questions  he  might  ask,  and  settle  in  his  own  mind,  it  would 
seem,  by  a  slight  examination.  Assertions,  no  matter  by  whom,  either 
upon  one  side  or  the  other,  would  of  course  be  of  no  avail ;  the  matter 
is  therefore  left  with  these  hints  of  some  of  the  points  to  which  a  person 
might  give  his  attention,  before  making  a  decision. 

t  One  case  is  at  present  in  mind,  where  a  boy  from  the  front  part  of 
the  brain  lost  more  than  half  a  teacupful  of  substance.  In  a  few  months 
he  was  well  and  attended  school,  making  as  rapid  intellectual  progress 
as  ever,  and  he  was  always  remarkable  for  proficiency  in  his  studies. 

10* 


226  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

628.  a.    There  is  a  very  large  quantity  of  blood  passing 
to  the  head ;  in  proportion  to  its  size,  from  five  to  ten  times 
as  much  as  passes  to  any  other  part  of  the  body,  except  the 
kidneys. 

b.  The  quantity,  as  already  stated,   increases  with  the 
activity  of  thought ;  and  vice  versa,  the  activity  of  thought  is 
increased  by  an  increase  of  the  rapidity  of  the  circulation. 

c.  The  blood  which  passes  to  the  head  is  of  one  quality, 
and  goes  through  one  set  of  vessels  j  the  blood  which  passes 
from  the  head,  is  the  same  in  quantity  but  differs  in  quality, 
and  comes  through  another  set  of  vessels :  that  is,  the  blood 
undergoes  a  change  as  it  is  passing  through  the  brain. 

It  would  seem  to  be  correctly  inferred,  therefore,  that  the  brain  had 
undergone  changes  corresponding  to  the  changes  in  the  blood  ;  and  that 
as  the  circulation  of  the  blood  corresponds  with  the  activity  of  thought, 
so  the  activity  of  thought  must  correspond  with  the  changes  which  take 
place  in  the  brain. 

629.  a.    If  the  blood  be  ever  so  large  in  quantity  in  the 
brain,  the  thoughts  are  not  active,  if  the  blood  be  stagnant — 
as  in  case  of  apoplexy — in  which  many  times  or  always,  the 
bloodvessels  of  the  head  are  crowded  with  blood,   but  the 
mind  is  inactive. 

J.  If  the  blood  have  not  been  properly  acted  upon  in  the 
lungs,  it  is  found  that  though  it  flows  through  the  brain  in 
sufficient  quantities,  a  person  becomes  insensible. 

The  inference  is,  therefore,  that  it  is  not  the  quantity  of  blood  which 
the  brain  receives,  merely ;  but  the  quantity  and  quality  of  the  blood 
which  prevents  or  facilitates  the  changes  in  the  brain  necessary  to  the 
production  of  thought. 

630.  a.    For  the  fulfilment  of  their  duties  in  a  perfect 
manner,  all  parts  of  the  body  depend  upon  the  blood. 

&.  As  in  case  of  the  muscles,  all  parts  are  found  to 
require  more  blood  when  active,  than  when  in  a  state  of 
repose. 


SEC.  1.]  THE  BRAIN.      -.«&  227 

c.  There  is  only  a  given  amount  of  blood  in  the  body  at 
any  one  time  ;  and  if  this  be  in  one  part,  it  cannot  be  in  an- 
other  at  the  same  time. 

It  is,  therefore,  inferred  that  when  the  blood  is  elsewhere  than  in  the 
brain,  the  thoughts  cannot  be  active  in  the  highest  degree ;  and  vice 
versa,  when  the  thoughts  are  active  and  producing  rapid  changes  in  the 
brain,  blood  in  large  quantity  is  then  required,  and  it  cannot  at  the  same 
time  be  allowed  to  circulate  rapidly  in  other  parts :  hence  the  feet  become 
cold,  the  food  in  the  stomach  is  not  digested,  and  muscular  exercise  can- 
not be  taken  with  profit.  Hence  severe  study  should  never  be  allowed 
just  before  or  after  a  repast  of  food,  or  during  the  active  performance 
of  duty  by  any  part  of  the  body  beside  the  brain.  While,  on  the  other 
hand,  a  person  should  not  direct  the  blood  to  any  other  part  of  the  body 
when  the  brain  requires  it  during  the  production  of  thought. 

631.  Only  a  small  portion  of  the  blood  is  adapted  to  take 
part  in  the  changes  produced  in  the  brain  during  mental 
operations. 

It  would  be  inferred  from  this,  that  the  production  of  thought  would 
be  limited,  not  only  by  the  quantity  of  blood  the  brain  received,  but  by 
the  quality  of  it ;  and  that  whatever  would  contribute  to  improve  the 
quality  of  the  blood,  would  equally  contribute  to  facilitate  the  production 
of  thought:  hence,  that  pure  air  and  a  healthy  condition  of  the  lungs 
would  be  necessary  for  the  perfect  accomplishment  of  mental  duties ;  and 
not  less  necessary  will  be  a  supply  and  healthy  digestion  of  wholesome 
food. 

632.  a.    Proper  exercise  of  the  muscles,  has  been  found 
to  have  a  favorable  effect  upon  the  thinking  powers. 

b.  It  has  been  already  seen  that  exercise  of  the  muscles 
furnishes  to  the  blood  a  supply  of  substance  no  longer  of  use 
to  the  muscle,  but  indeed  a  detriment  if  allowed  to  remain 
in  the  muscle. 

It  might  be  inferred,  that  among  other  ways  in  which  exercise  of  th« 
muscles  and  other  parts  benefited  the  brain,  one  was  that  of  supplying 
the  blood  with  substances,  which  though  no  longer  useful  to  the  muscle, 
might  serve  a  purpose  in  effecting  the  important  changes  which  thinking 
produces  in  the  brain ;  and  so  on  the  other  hand,  may  the  results  of  th« 
changes  in  the  brain  assist  in  perfecting  the  muscles. 


228  ORGANS.  WITS  WHICH  TO  THIPCK.  [CHAP.  III. 

633.  a.    Time  is  necessarily  required  in  producing  the 
changes  which  take  place  in  the  brain  during  thinking. 

b.  After  intense  thinking  for  a  time,  the  thoughts  become 
confused ;  but  after  a  repose,  they  are  again  rapidly  pro- 
duced in  a  regular  manner. 

The  inference  is,  that  the  power  of  producing  thought  is  limited  not 
only  by  the  quantity  and  quality  of  the  blood,  but  by  the  length  of  time 
required  to  re-periect  the  brain  ;  and  that  the  best  time  for  thought  and 
study  will  be  in  the  early  part  of  the  day,  after  the  repose  of  the  night — 
and  after  a  little  exercise  has  been  taken  to  circulate  the  blood  through 
the  entire  system,  in  some  parts  of  which  it  may  have  become  stagnant, 
BO  to  speak,  during  the  night. 

634.  a.  The  powers  of  different  persons  are  very  dif- 
ferent in   respect  to  the  offices  of  the  lungs,  the  digestive 
organs,  the  circulation,  the  blood,  &c. 

b.  In  the  same  person  the  health  affects  the  lungs,  the 
stomach,  &c.,  in  the  performance  of  their  duties,  and  intense 
thinking  soon  exhausts  the  powers  of  the  brain. 

c.  If  the  body  be  rapidly  growing,  it  is  necessary  that 
the  blood  should  circulate  very  freely  through  the.  growing 
parts  especially,  as  some  of  the  ingredients  required  by  the 
growing  parts  exist  in  the  blood  in  only  very  small  quantities; 
the  blood  must  not,  therefore,  be  monopolized  by  the  brain, 
and  thinking  will  soon  exhaust  it. 

It  is  to  be  inferred,  therefore,  that  one  person  will  require  more  fre- 
quent and  longer  repose  than  another ;  that  in  ill  health  longer  and  more 
frequent  repose  will  be  required  than  in  health,  and  that  in  childhood, 
very  frequent  intervals  of  repose  will  be  required,  and  it  is  also  to  be 
inferred,  that  compelling  active  thought  and  intense  thinking  for  a 
long  while,  in  case  of  a  child,  will  sacrifice  the  welfare  of  the  various 
parts  of  the  hody,  and  undermine  those  organs,  the  vigorous  action  of 
which  is  necessary  to  sustain  the  efforts  of  the  mind  in  mature  years.* 


*  It  unfortunately  happens  that  those  children  with  a  .brain  altogether 
too  active  for  their  age,  are  urged  many  times  to  study  instead  of  being 
encouraged  in  those  exercises  which  would  turn  the  flow  of  blood  from 


SUC.  1.]  THE  BRAIN.  229 

635.  a.  Intense  thought  for  a  long  time  is  attended  with  a 
fulness  and  heat  of  the  head,  from  which  the  application  of 
cold  gives  relief. 

b.  In  such  cases  the  slightest  exposures  sometimes  bring  on  the  most 
alarming  diseases. 

From  this  it  is  to  be  inferred,  that  a  very  active  circulation  of  blood 
through  the  brain,  at  last  produces  a  measure  of  stagnation  of  the  blood, 
or  a  distended  state  of  the  bloodvessels  of  the  head,  which  prevents  the 
proper  changes  of  the  brain,  and  of  course,  the  production  of  regular 
thought,  and  brings  the  brain  to  the  brink  of-  disease  ;  and  that  to  pre- 
vent this,  it  is  very  important  not  only  that  intervals  of  repose  be  given 
to  the  brain,  in  which  to  recover  its  perfection  ;  but  also,  that  the  inju- 
rious effects  of  too  active  circulation  of  blood  through  the  brain  le  pre- 
vented by  vigorous  exercise  of  other  parts  of  the  body,  especially  the 
MUSCLES  ;  for,  as  during  their  exercise  they  require  the  blood  in  large 
quantities,  it  will  be  drawn  off  from  the  brain.  Thus  on  the  one  hand, 
the  heat  of  the  head  will  be  lowered,  and  that  of  the  other  parts  of  the 
body  raised  ;  and  as  the  student  is  so  constantly  on  the  verge  of  too 
active  circulation  through  the  head,  he  must  avoid  every  other  cause 
besides  study  which  tends  to  increase  the  flow  of  blood  through  the  head, 
whether  it  be  in  the  form  of  a  glass  of  wine,  an  overloaded  stomach,  or 
a  "  common  cold."  Indeed,  over  the  desk  of  every  student,  and  every 
business  man,  it  should  be  inscribed  in  golden  letters,  "  KEEP  THE  FEET 

WARM   BY   EXERCISE   AND   THE   HEAD   COOL   BY   TEMPERANCE."      It  IS  also  to 

be  inferred,  that  the  child  should  have  frequent  moments  of  relaxation 
devoted  to  exercise  of  its  lungs,  its  muscles,  etc. 

636.  As  the  muscles  when  first  used,  or  unfrequently 
used,  do  not  receive  the  blood  in  proper  quantity,  but  as  by 
exercise,  increased  from  time  to  time,  the  vessels  become 
larger,  and  the  flow  of  blood  through  them  greater,  and  the 
muscles   capable  of  perfecting   themselves,  in   accordance 
with  what  is  required  of  them : — so,  also,  does  the   brain 
become  capable  of  accomplishing  more  and  more,  by  grad- 


the  over  active  brain  to  the  undeveloped  parts  of  the  body,  which  being 
strengthened,  will  labor  in  the  service  of  the  brain  with  great  effect  at  the 
period  of  maturity. 


1&30  ORGANS  WITH  WHICH  TO  THINK.  [cHAP.  III. 

ually  increased  exercise,  while  every  attempt  to  overdo,  ex- 
hausts and  diminishes  the  powers  of  the  brain. 

Hence  children  should  not  be  overtasked  with  studies,  for  as  the 
growth  of  other  parts  of  the  body  is  stunted  by  too  severe  labor,  so  is 
the  brain  prevented  from  developing  its  powers  by  too  assiduous  mental 
application  in  early  life ;  and  those  who  enter  upon  a  course  of  study, 
must  accustom  the  brain  to  its  duties  by  slow  degrees. 

637.  Mental   exercise  is  attended  by  increased  circula- 
tion of  the  blood,  which  does  not  at  once  subside,  as  is  seen 
in  the  continued  excitement  once  produced  by  any  cause. 
It  is,  however,  reduced  by  exercise  of  the  muscles,  &c.,  by 
cold  applications  to  the  head,  and  warm  applications  to  the 
feet. 

It  is  hence  to  be  inferred,  that  study  should  not  be  engaged  in  for  a 
time  previous  to  the  hour  of  retiring  to  sleep,  as  quiet  of  the  brain  is 
desirable  in  order  to  secure  quiet  of  the  mind.  Also,  that  gentle  muscu- 
lar exercise,  wanning  the  feet,  rubbing  the  skin  briskly,  and  a  cool 
application  to  the  head,  will  subdue  the  circulation  of  blood  through  the 
brain.  To  do  some  or  all  these  things  just  before  retiring,  is  desirable 
on  the  part  of  all,  but  especially  should  they  be  done  by  any  person 
subject  to  apoplexy,  or  fits  of  any  kind,  dreams,  disturbed  sleep,  or  any 
of  the  causes  of  wakefulness. 

638.  a.  When  a  man  becomes  insensible  from  intoxication, 
he  is  brought  to  his  senses  by  cold  applications  to  his  head, 
and  heat  applied  to  his  feet  and  hands. 

b.  When  a  person  has  taken  opium  and  becomes  stupid, 
or  sleepy,  he  is  roused  by  rubbing,  by  heat  applied  to  his 
hands  ani  feet,  and  by  cold  applied  to  his  head. 

c.  When  the  physician  is  called  to  a  man  in  a  fit  of 
apoplexy,  he  rubs  him,  applies  heat  to  his  feet  and  hands, 
and  perhaps  draws  blood. 

From  these  things  it  is  safe  to  infer,  that  when  a  person  is  stupid  or 
insensible  from  any  cause  of  disease  or  accident,  it  is  proper  to  use.  thos» 
means  which  will  draw  the  blood  from  the  brain  into  other  parts  of  the 
body,  viz.,  keep  the  head  cool,  rub  the  skin,  and  make  warm  applica- 
tions to  the  extremities,  and  if  the  case  be  severe,  let  blood  flow  out  of 


SEC.  1.]  THE  BRAIN.  231 

the  system  altogether.  Especially  it  is  important  when  a  person  has 
met  with  any  accident  to  the  head,  such  as  a  severe  blow,  though  the 
skull  has  not  been  fractured,  that  the  head  be  kept  cool,  and  the  brain 
kept  from  exercise  that  shall  tend  to  draw  the  blood  to  the  head,  and 
the  skin  generally,  but  the  feet  in  particular,  from  exposure  to  the  cold.* 

639.  We  may  now  consider  the  sensations  produced  by 
those  parts  of  the  brain  employed  in  thinking.     They  are  of 
three  kinds,     a.  When  the  mind  is  exercised  according  to  the 
laws  already  inferred,  the  most  satisfactory  and  delightful 
sensations  are  experienced.    To  think;  and  acquire  knowledge 
is  the  sphere,  the  duty  of  man,  to  think   and  acquire  know- 
ledge is  also  his  highest  pleasure. 

We  are  therefore  to  infer,  that  when  changes  of  the  brain  take  place 
in  accordance  with  its  best  welfare,  such  a  state  is  produced  in  the  brain 
as  acting  on  the  mind  causes  agreeable  sensations,  and  a  desire  to  do  that 
which  shall  be  productive  of  such  pleasurable  results. 

640.  b.  When  the  mind  is  over-tasked,  mental  fatigue  is 
produced,  and  an  intense  desire  for  repose,  until  at  last,  all 
effort  to  continue  the  process  of  thinking  is  overcome,  and 
"  tired  nature's  sweet  restorer,  balmy  sleep,"  comes  to  the 
relief  of  body  and  mind. 

Hence  it  may  be  inferred,  that  when  the  changes  of  the  brain  have 
been  carried  to  that  degree  which  is«  injurious,  they  produce  a  state  which, 
acting  on  the  mind,  causes  disagreeable  sensations,  which  at  last  over- 
come the  exercise  of  the  most  determined  will,  thus  acting  as  their  own 
regulator. 

641.  c.  When  the  mind  is  not  engaged  in  thinking,  it  soon 
feels  an  uneasiness,  an  unsatisfied  want,  a  desire  to  perceive 
sensations,  which  must  be  gratified,  for  it  is  the  nature  of 


*  A  case  occurred  last  summer,  in  illustration.  A  young  man  was 
kicked  on  the  head  by  a  horse.  He  was  doing  well ;  the  physician 
ordered  his  head  kept  cool  by  cold  cloths,  and  advised  him  not  to  leave 
his  room  ;  but  feeling  well  one  pleasant  afternoon,  he  laid  off  the  cloths, 
went  into  a  back  kitchen  with  earthen  floor,  and  sat  with  his  bare  feet 
upon  the  ground  and  his  head  near  a  heated  cooking-stove,  for  some 
time.  It  was  the  cause  of  his  death. 


232  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

man  to  desire  to  perceive  new  sensations.  As  the  old  proverb 
is,  "  Those  who  have  nothing  to  do,  will  do  mischief."  The 
plaything  received  by  the  child  is  turned  on  every  side  and 
torn  in  pieces  that  it  may  produce  new  sensations,  and  when 
it  knows  all  it  can  in  regard  to  the  thing,  it  is  cast  aside  and  a 
new  article  demanded.  This  desire  is  usually  called  a  nat- 
ural curiosity  ;  but 

It  may  be  inferred  that  the  brain  is  so  constituted  as  to  produce  sen- 
sations of  uneasiness  when  those  changes  have  not  taken  place  in  the 
brain  which  are  for  the  good  of  man,  by  the  cultivation  of  his  mind  at- 
tendant upon  a  certain  action  and  changes  of  the  brain. 

642.  The  man  therefore  who  gains  the  idea  that  ac- 
quiring knowledge  is  not '  for  him,  does  not  understand 
his  nature,  the  constitution  of  his  mind  and  brain ;  he  talks 
of  the  weather,  he  goes  in  and  comes  out,  rises  up  and  sits 
down,  yokes  himself  reluctantly  to  labor,  and  wonders  why 
he  was  made  a  slave,  to  work,  to  drudge,  like  the  horse  that 
toils  by  his  side.  He  is  mistaken.  He  was  not  made  so  to 
be.  His  horse  is  thoughtless,  and  while  he  is  thoughtless, 
how  can  he  claim  more  than  his  fellow  animal  ?  But  let 
him  awake  to  the  importance  of  his  estate,  enter  the  walks 
of  useful  knowledge,  exercise  his  mind  and  brain  gradually 
till  both  mutually  assisting  to  develop  each  other,  reach  ma- 
turity, and  he  will  find  there  are  no  "  common  men"  but 
those  who  satisfy  themselves  with  the  mere  physical  enjoy- 
ments of  animals,  which  perhaps  even  the  oyster  may  share 
vith  them — but  that  whoever  makes  study  his  diversion 
and  the  pursuit  of  wisdom  his  satisfaction,  according  to  the 
intentions  of  the  Creator,  will  have  the  noblest  spirits  of  the 
past  and  present  ages  for  his  intimate  friends,  and  raise  him- 
self to  a  point  of  eminence  from  which  he  can  "  look  up"  to 
no  being  but  God. 

643.  Whoever  likewise,  pictured  the  temple  of  science 
on  a  steep  and  stony  hill,  up  which  a  long  life  the  student 


SEC.  1.]  THE  BRAIN.  233 

must  drag  his  weary  steps  to  reach  the  summit,  and  then  be 
satisfied  with — what? — a  wreath  bestowed  upon  his  ambition! 
knew  not  the  nature  of  man  nor  how  to  open  before  him  the 
gates  to  the  smooth  and  sunny  paths  of  science,  where  flow- 
ers and  fruits  abound  on  every  hand,  not  as  delicious  near 
the  entrance,  as  farther  on,  for  every  step  proves  more  se- 
ductive, but  such  as  are  well  adapted  to  the  relish  of  the 
mind  commencing  its  progress.  Commend  me  to  the  teacher 
whose  scholars  will  cry  if  kept  at  home,  and  save  my  chil- 
dren from  one  who  thinks  he  must  drag  the  unwilling  votary 
to  bend  in  worship  before  the  shrine  he  has  wrongly  learned 
to  hate.  Disgust  of  thinking  will  be  produced  when  the 
mind  is  compelled  to  apply  itself  against  every  law  of  nature, 
when  the  body,  the  brain  of  which  the  mind  is  to  think  with, 
is  so  placed  that  it  must  constantly  warn  by  aches  and  wea- 
riness, of  the  harm  it  is  suffering,  when  the  buoyancy  and 
playfulness  of  youth  are  denied  their  action,  and  after  all, 
not  that  the  mind  may  be  caused  to  think,  but  made  to  con 
something,  to  "  learn  by  heart"  what  is  not  understood,  in 
short,  to  encounter  all  the  drudgery,  but  not  arrive  at  the 
pleasure  of  thinking. 

644.  Every  thing  about  the  student  should,  on  the  other 
hand,  be  pleasant,  and  every  agreeable  sensation  of  sigh4, 
sound,  &c.,  should  in  its  place,  for  it  has  a  place,  be 
made  to  add  to  the  delight  of  fulfilling  this  important  duty 
of  man — cultivating  a  desire  to  obtain  knowledge,  cultivating 
a  pleasure  in  the  exercise  of  the  mind  and  brain.  School 
houses  should  be  in  pleasant  situations,  should  be  comfortably 
and  attractively  furnished,  and  abundant  opportunity  allowed 
for  physical  recreation,  and  the  grand  principle,  acted  upon, 
that  The  human  mind  can  better  be  led  than  driven  to  the 
acquirement  of  knowledge,  or  another  still  more  excellent  but 
embracing  the  same  idea :  "  To  please  is  the  first  step  to- 
wards instructing." 


234  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

645.  In  the  attempts  to  reform  society,  it  is  too  frequently 
forgotten  that  the  cause  of  vice,  many  times,  is  want  of  oc- 
cupation. The  mind  will  have  sensations  produced,  and 
cannot  bear  the  ennui  of  "nothing  to  do."  Cultivate,  in 
younger  or  older,  the  desire  to  acquire  knowledge,  the  power 
and  pleasure  of  thinking,  and  the  mind  will  always  find 
something  wherewith  to  occupy  itself.  The  world  around 
upon  the  murkiest  day,  or  the  wonders  of  his  own  body,  will 
afford  subjects  to  the  thinking  man,  such  that  he  will  never 
be  ready  for  the  setting  sun.  But  if  the  mind  be  not  in  the 
habit  of  thinking,  the  instant  the  young  man  is  free  from  his 
business  or  his  labors,  he  is  solicited  to  the  haunts  of  dissipa- 
tion, where  the  delirium  of  strong  drinks  and  the  accompa- 
nying revelry  may  make  the  mind  forget  its  self- weariness — 
for  the  worst  of  burdens  is  an  unoccupied  mind.  Hence  it 
is  better  for  the  public  to  educate  the  ignorant,  than  to  sup- 
port them  as  paupers  or  criminals — for  the  ignorant  are  al- 
most sure  to  become  either  paupers  through  dissipation,  or 
criminals,  by  putting  their  hand  to  mischief  rather  than  want 
something  to  "  drive  dull  care  away." 

G46..  We  may  now  consider  the  emotions : 

a.  The  language  of  the  emotions  is  uniform — the  tearful 
eye  is  the  language  of  pity,  &c. 

b.  The  emotions  exhibit  themselves  by  increasing  or  di- 
minishing the  health  of  the  system.     Dr.  Beaumont  testifies, 
that  "  anger  would  check  the  digestive  process  sometimes  for 
an  hour ;"  and  melancholy  feelings  are  universally  known  to 
depress  the  action  of  all  parts  of  the  body,  while  lively  emo- 
tions invigorate.    Says  some  old  philosopher — "  Every  hearty 
laugh  draws  a  nail  from  a  person's  coffin,  while  every  sigh 
drives  two  in."     Indeed  it  will  be  found,  that  all  those  emo- 
tions which  tend  to  render  a  person  a  good  member  of  soci- 
ety, tend  to  improve  health  and  beauty,  and  to  lengthen  life ; 


SEC.  1.]  THE  BHAIN.  235 

while  all  those  which  tend  to  promote  selfishness,  such  as 
anger,  revenge,  &c.,  depress  health  and  shorten  life. 

It  may  be  inferred  that  the  brain  is  active  when  the  emotions  are 
active,  and  in  a  degree  corresponding  with  them,  and  that  man  is  intend- 
ed to  live  in  society,  and  that  the  true  refinements  of  civilized,  educated 
society,  are  most  conducive  to  health  and  longevity. 

647.  Uneducated  persons  exhibit  emotions  of  every  kind 
in  the  highest  degree. 

It  is  to  be  inferred,  that  that  condition  of  mind  and  brain  most  pro- 
per for  developing  thought,  is  not  necessary  for  the  exhibition  of  emo- 
tions. 

648.  a.  When  the  exhilarating  or  exciting  passions  are  ex- 
hibited, there  is  evidence  of  a  very  rapid  circulation  of  blood 
through  the  head,  but  when  the  depressing  emotions  are  ex- 
hibited it  is  quite  the  reverse. 

b.  After  the  exciting  passions  have  continued  for  a  time, 
they  produce  exhaustion  of  the  most  decided  character. 

From  these  things  it  is  inferred,  that  as  in  case  of  thinking,  so  in  the 
exercise  of  the  emotions,  there  are  changes  produced  in  the  brain,  if  the 
emotions  are  of  an  exciting  character ;  while  if  they  are  depressing,  not 
only  are  changes  of  one  kind,  but  of  various  kinds,  checked  or  altogether 
prevented.  It  would  also  be  inferred,  that  in  different  persons,  and  in 
the  same  person  at  different  times,  the  emotions  would  differ  very  much 
in  intensity.  Especially  when  the  brain  is  inflamed  or  the  nervous  sys- 
tem easily  excited,  it  would  be  expected  that  the  emotions  would  be 
easily  excited  and  rendered  intense  ;  that  in  females  the  emotions  would 
be  more  easily  excited,  more  acute,  and  less  enduring,  than  in  man. 
Some  would  infer  that  the  emotions  are  almost,  if  not  entirely,  physical 
— a  weakness  of  the  body  that  strength  of  mind  is  wanted  to  control ; 
but  it  will  be  seen  by  the  following  paragraph,  that  the  mind  is  the  cause 
of  emotions,  and  the  brain  merely  the  instrument. 

649.  The  signs  of  the  emotions  can  only  be  perfectly 
produced  by  exciting  emotions  in  the  mind.     A  person  can- 
not cause  the  tears  of  pity  to  flow,  without  the  feelings  of 
pity  are  first  produced ;    while  if  a  person  think  of  objects 
which  will  move  his  pity,  the  tears  flow  as  a  natural  effect. 


236  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

Persons  who  try  to  counterfeit  the  signs  of  pity  do  not  suc- 
ceed. Actors,  instead  of  laboring  to  counterfeit  the  signs  of 
the  emotions,  strive  to  counterfeit  the  emotions,  or  more  pro- 
perly speaking,  cultivate  the  power  of  producing  real  emo- 
tions, whenever  it  is  desirable,  and  the  emotion  once  pro- 
duced, the  signs  of  it  are  exhibited  as  a  matter  of  course, 
and  without,  effort. 

From  this  it  is  to  be  inferred  that  the  mind  is  active  in  the  produc- 
tion of  emotions,  and  that  the  facility  of  producing  emotions  can  be  easily 
cultivated  ;  also,  that  as  certain  emotions  are  healthful,  they  should  be 
cultivated  in  the  child  by  the  parent,  and  in  every  one  by  himself;  that 
the  mode  of  cultivating  the  emotions  is  to  present  before  the  mind  objects 
calculated  to-  excite  the  desirable  emotion  ;  and  that  a  speaker  who 
wishes  to  be  impressive,  must  not  study  so  much  how  to  make  the  ges- 
tures of  emotion,  as  to  feel  the  emotions  he  wishes  to  have  act  upon  his 
hearers,  when  the  gestures  will  be  properly  made  as  a  necessary  con- 
sequence ;  and  the  hypocrite  may  infer  that,  though  he  may  "  smile  and 
smile,"  such  language  not  being  produced  by  real  emotions,  has  a 
"  brogue  "  which  shows  decidedly  his  true  character. 

650.  Those  parts  of  the  brain  employed  by  the  mind  in 
the  production  of  emotions,  cause  in  the  mind  four  kinds  of 
sensations. 

a.  A  pleasurable  sensation  when  the  indulgence  of  the 
emotion  is  for  the  good  of  the  individual  and  of  society. 

From  this  it  is  to  be  inferred,  that  the  constitution  of  the  brain  is  such 
that  the  changes  taking  place  in  it,  under  the  action  of  the  proper  emo- 
tions, produce  such  a  state  as  is  agreeable  to  the  mind.  If,  therefore,  a 
similar  state  of  the  brain  be  produced  by  disease,  or  the  action  of  medi- 
cine, th«  same  feelings  might  be  experienced.  Hence  we  see  that  some 
diseases  produce  sensations  as  if  emotions  of  the  happiest  character  ex- 
isted. 

C51.  I.  The  exercise  of  the  emotions  to  a  certain  degree 
produces  feelings  of  exhaustion. 

From  this  it  would  be  inferred,  that  too  long  continued  exercise  of 
the  emotions  produces  harmful  changes  of  the  brain,  which  time  alono 
can  re-perfect.  When,  therefore,  wine  or  the  like  is  used  to  produce  such 


SEC.  1.]  THE  BRAIN.  237 

a  state  of  the  brain  that  the  exhaustion  is  no  longer  felt,  and  an  excited 
state  of  the  emotions  may  be  continued,  as  when  the  same  is  done  that 
a  person  may  study  after  fatigue  is  produced,  the  most  harmful  conse- 
quences will  result ;  sometimes  such  exhaustion  of  the  mind  and  brain, 
that  it  can  never  be  restored.  It  would  also  be  inferred,  that  cool  appli- 
cations to  the  head  and  warm  applications  to  the  feet,  rubbing  the  skin, 
and  gentle  muscular  exercise,  would  be  advisable  under  such  circum- 
stances, and  especially  before  retiring  for  sleep,  if  the  emotions  have  been 
active. 

652.  c.  Certain  degrees  and  certain  kinds  of  emotions 
are  disagreeable. 

It  is  to  be  inferred  that  certain  states  of  the  brain,  viz.,  such  as  exist 
in  case  of  the  emotions  referred  to,  are  intended  to  produce  disagreeable 
sensations.  If,  therefore,  the  same  state  of  the  brain  be  produced  by 
disease,  the  same  sensation  will  be  caused,  and  the  sensations  being  sim- 
ilar, the  cause  will  many  times  be  thought  to  be  the  same.  But  melan- 
choly feelings  may  be  produced  by  disease  of  the  stomach,  or  other 
parts  of  the  body,  and  also  by  the  sorrows  of  the  mind.  To  remove 
these  feelings,  it  is,  therefore,  sometimes  necessary  to  remove  physical 
disease,  and  sometimes  to  direct  the  attention  of  the  mind  from  the 
cause  of  its  affliction,  by  causing  sensations  which  are  of  a  different  char- 
acter to  overpower  those  resulting  from  its  sorrowful  state.  Hence  why, 
for  desponding  states  of  the  mind,  the  physician  advises  riding,  jour- 
neying, new  scenes,  new  faces,  and  whatever  shall  cause  a  variety  of 
agreeable  sensations,  while  in  other  cases  a  dose  of  medicine  effects  a 
cure.  Hence  is  seen  why  changes  in  weather,  by  conducing  to  a  certain 
state  of  the  brain,  will  cause  desponding  feelings,  from  which  a  person 
only  recovers  with  the  return  of  fair  weather. 

653.  d.  When  under  proper  circumstances  the  brain  is 
not  exercised  by  certain   emotions,  it  causes  sensations  of 
uneasiness — a  want  that  cannot  be  satisfied  till  the  desirable 
exercise  of  the  brain  is  allowed.     Thus  the  mind  must  love 
at  a  certain  period  of  life,  and  must  have  something  to  love. 
The  most  ardent  attachment  is  sometimes  seen  for  a  dog-  a 
horse,  and  those  who  are  very  dissimilar,  to  each  other,  as 
husband    and  wife,  will   love   each    other   most   devotedly. 
There  is  inexpressible  delight  in  the  exercise  of  this  emotion, 


238  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

and  want  of  its  exercise  is  insufferable  by  most  of  the  hu- 
man species. 

From  this  it  is  to  be  inferred,  that  nature  has  constituted  the  brain 
in  such  a  manner,  that  if  the  changes  which  take  place  in  it  when  the 
emotions  are  active,  are  not  produced,  it  will  cause  uneasy  sensations, 
such  as  will  at  last  compel  a  person  to  exercise  those  emotions,  which 
are  for  his  own  good  and  that  of  his  race. 

654.  We  may  now  take  notice  of  both  the  emotions  and 
the  thoughts. 

a.  It  will   be  observed,  that  deep   thought  and   intense 
emotion  cannot  take  place  together. 

b.  It  will  also  be  noticed  that  excitement  of  the  emotions, 
from  time  to  time,  relieves  from  the  fatigue   of  profound 
thought. 

From  these  things  it  would  be  inferred,  that  the  same  parts  of  the 
brain  are  not  engaged  in  the  production  of  thoughts  and  emotions. 

655.  If  an  idea  which  may  either  awaken  thought  or 
emotion,  be  presented  before  a  multitude  even  of  educated 
persons — emotions  rather  than  thoughts  will  be  exerted  in  a 
large  majority.     Emotion  is  also  exhibited  earlier  than  deep 
thought ;   and  by  the  most  uneducated,  in  an  intense  degree. 

It  is  to  be  inferred  from  this,  that  the  parts  of  the  brain  employed  in 
the  exercise  of  the  emotions,  are  more  easily  brought  into  action  than  the 
parts  employed  in  thinking.  That  the  emotions  are  the  nearest  avenues 
to  the  human  mind,  and  the  means  by  which  many  times  thoughts  can 
be  awakened  ;  for,  if  by  exciting  the  emotions,  an  active  flow  of  blood 
through  the  brain  be  produced,  an  increased  flow  must  be  received  by 
the  organs  of  thought,  and,  as  we  have  seen,  the  circulation  of  blood 
through  them  prompts  to  thought.  Hence,  when  a  speaker's  emotions 
are  warm,  they  assist  his  thoughts. 

656.  We  may  now  refer  to  the  fact,  that  the  attention 
of  the  mind  may  be  given  either  to  the  sensations  produced 
by  thinking,  by  exercising  the  emotions,  or  by  the  action  of 
the  physical  senses  ;  and  it  will  be  found,  that  as  the  plea- 
sure   resulting  from  these  last  is   the   lowest,  so  it  is  the 


SEC.  1.]  THE  BRAIN.  239 

most  universal.  It  will  also  be  found,  that  as  the  attention 
of  the  mind  of  the  majority  will  be  arrested  sooner  by  a 
cause  which  excites  emotion,  than  by  one  which  excites 
thought ;  so  it  will  be  arrested  more  quickly  by  any  thing 
acting  upon  the  physical  senses,  than  by  any  cause  exciting 
the  emotions.  This  indeed  is  the  order  in  which  attention 
should  be  arrested.  Our  physical  senses  warn  us  of  imme- 
diate danger  to  ourselves.  Our  emotions  excite  us  to  protect 
society ;  while  thought  must  take  place  without  haste,  and 
with  time  for  deliberation. 

657.  The  attention  of  the  young  child  is  chiefly  to  be 
occupied  with  physical   sensations,  as  those   are  very  early 
produced,  and  may  be  indulged  without  danger  of  overwork- 
ing the  brain  ;   and  it  should  be  kept  in  mind,  that  while  the 
mind  is  occupied  with  one  sensation  it  cannot  be  with   an- 
other.    If,  therefore,  the  mind  be  occupied   with  sensations 
produced  by  causes  of  a  harmless  character,  the  child  will 
not  cry  for  articles  to  eat,  &c.     As  the  child  grows  older,  its 
emotions  may  be  cultivated  and  the  mind  satisfied  therewith ; 
and  as  time  advances,  it  may  be  gently  led  to  think  and  to 
increase  its  desire  for  obtaining  knowledge,  and  applying  it 
for  its  own  and  others'  good. 

658.  As  in  case  of  the  muscles  by  exercise,  gently  and 
gradually  increased  in  early  years,  the  muscular  man  is 
produced,  who  not  only  uses  his  muscles  with  efficiency  but 
delights  in  their  exercise :   so  should  the  brain  be  fitted  m 
early  years,  by  gentle  and  gradually  increased  exercise  in 
the  fulfilment  of  all   its  duties  of  thinking,  feeling  emotions, 
and  giving  attention  to  physical  sensations,  to  enjoy  as  it  in- 
creases in  years,  all  the  pleasure  which  the  world  and  its 
own  powers  are  capable  of  producing.     For  though  we  know 
not  on  what  peculiar  property  of  the  nervous  substance  its 
powers  of  acting  depend,  or  what  particular  requirements 
are  necessary  in  the  fulfilment  of  its  duties  ;   though  it  is 


240  ORGANS  WITH  WHICH  TO  THINK.  [CHAP.  III. 

generally  dented  to  increase  in  size  by  exercise — and  it 
would  seem  correctly — yet  it  would  also  seem,  and  I  believe 
it  will  be  universally  allowed,  to  be  improved  in  its  powers, 
by  exercise ;  and  by  gentle  exercise  in  youth  while  it  is 
growing,  it  is  natural  to  suppose  that  its  powers  would  re- 
ceive a  favorable  direction,  and  be  developed  in  a  higher 
degree,  than  if  its  cultivation  be  neglected  till  advanced 
years. 

659.  In  the  fulfilment  of  all  the  duties  of  the  mind,  the 
blood  being  required  by  the  brain  in  large  quantity  and  of  a 
pure  quality ;  not  only  must  attention  be  given  to  develop  the 
mind  by  its  own  exercise,  but  to  develop  the  powers  of  its 
organ,  the  brain,  by  muscular  action,  healthy,  pure  air — and 
in  large  quantities — taking  wholesome  food  with  a  health, 
fully  produced  appetite,  by  the  use  of  nature's  beverage  as  a 
drink,  great  attention  to  cleanliness  and  activity  of  the  skin, 
and  an  undeviating  observance  of  the  best  habits  in  every 
respect. 


SECTION  2. — The  Mind. 

660.  The  duty  of  the  mind  in  the  production  of  thoughts,  emotions, 
and  sensations,  or  the  mode  of  fulfilling  the  duty,  cannot  be  specified. 
Whether  the  nature  of  the  mind  is  different  in  different  individuals,  or 
whether  its  apparent  difference  is  owing  entirely  to  the  constitution  and 
state  of  the  brain,  is  disputed.     That  mental  operntions  depend  a   great 
deal  upon  the  state  of  the  brain,  is  conclusive  ;  but  some  suppose   that 
certain  duties  of  the  mind  are  accomplished  by  the  mind  itself,  without 
the  employment  of  the  brain. 

661.  Some  think  that  the  mind  is  a  unit,  others  think  that  it  may  be 
considered  as  possessing  faculties,  one  of  which  may  be  more  efficient 
than  the  same  faculty  belonging  to  other  minds.     Some  think  also  that 
exercise  strengthens  these  faculties  of  the  mind.     Some  think  that  the 
different  faculties  make  use  of  different  parts  of  the  brain,  and  that  of 
course  there  are  as  many  divisions  of  the  brain  as  there  are  faculties  of 


SEC.  2.]  THE  MIND.  241 

the  mind.  Some  suppose  that  the  faculties  can  be  exercised  separately, 
and  thus  are  invigorated,  while  others  may  be  enfeebled  by  want  of  ex- 
ercise. 

662.  But  in  practical  treatment  of  the  body,  all  these  persons  very 
fortunately  perfectly  agree  ;  and  the  rules  laid  down  for  the  exercise  of 
the  mind,  perfectly  correspond  with  those  by  which  exercise  of  the  brain 
should  be  regulated.  It  is  very  happy  for  the  physiologist,  therefore,  that 
it  is  not  his  duty  to  discuss  the  subjects  of  mental  or  moral  philosophy, 
but  that  it  is  his  privilege  to  leave  those  profound  departments  of  know- 
ledge in  the  hands  of  those  learned  men  who  have  shown  their  ability  to 
handle  them  with  the  most  flattering  success.*  . 

*  There  is  one  thing,  however,  in  respect  to  which  the  physiologist 
and  physician  must  be  humored.  They  must  be  allowed  to  maintain  that 
insanity  is  the  result  of  disease,  that  though  it  may  be  caused  by  the 
mind,  yet  it  never  exists  till  disease  has  been  produced  ;  and  the  indi- 
vidual exhibiting  insanity  should  be  considered  as  afflicted  with  disease, 
and  looked  upon  with  pity,  not  frowned  upon  by  friends  and  neighbors 
as  if  he  were  laboring  under  some  curse,  nor  should  any  unwillingness  be 
felt  by  friends,  or  a  person  himself,  to  allow  that  insanity  exists,  if  it 
really  do — not  more,  that  is  to  say,  than  in  allowing  the  existence  of  any 
disease.  Those  noble  institutions  erected  by  many  of  our  States,  usually 
afford  the  best  aid  in  the  restoration  of  the  sick  who  exhibit  insanity ; 
and  it  is  well  to  take  advantage  of  them  before  the  disease  has  been 
long  fixed,  as  the  cure  is  at  first  easily  effected  in  many  cases,  which, 
neglected  in  the  outset  from  the  wrong  views  of  insanity  that  many  en- 
tertain in  not  considering  it  a  disease,  never  recover. 


11 


BOOK  II. 

SECOND   CLASS   OF   ORGANS. 

GENERAL   OBSERVATIONS. 

1.  The  organs  described  in  the  first  book,  require  that 
four  duties  should  be  performed  in  respect  to  them. 

2.  1st.  They  must  be  preserved  of  a  proper  temperature. 
For  when  the  skin  becomes  cold,  the  sensations  are  evidently  blunted, 

a  person  rendered  irritable,  &c.     If  the  head  be  hot  it  aches,  and  thought 
is  confused. 

3.  2d.  The  various   parts  of  the  body,  as  they  become 
unfit  for  use,  must  be  cast  out  of  .the  system.     This  process 
is  called  excretion. 

For  it  has  been  shown  that  action  of  the  brain,  the  muscles,  and  it 
is  supposed  of  any  part,  is  attended  with  a  wearing  out,  so  to  speak,  of 
portions  of  the  part  used. 

4.  3d.  The  parts  which  have  become  unfit  for  use  and 
are  removed,  must  be  replaced  by  new  material  fit  for  use. 
Doing  this  is  called  the  process  of  nutrition.     The  substance 
with  which  it  is  done  is  called  nutritive  substance,  nutri? 
ment,  &c. 

5.  4th.  During  the  early  periods  of  life  the  various  parts 
of  tho  body  must  increase  in  size ;  accomplishing  this,  is  also 
called  the  process  of  nutrition,  and  the  substance  with  which 
it  is  done  is  called  nutriment. 


244  GENERAL  OBSERVATIONS. 

6.  How  the  temperature  of  the  body  is  preserved,  will  be  understood 
by  observing  the  habits  of  man  and  animals  in  different  parts  of  the 
world.     The  first  thing  that  strikes  a  person  is,  that  nature  has  given 
man  reason  and  ingenuity,  by  exercise  of  which  he  clothes  himself,  and 
protects  himself  and  his  domestic  animals  from  the  weather. 

7.  In  respect  to  animals,  it  is  observed  that  nature  has  given  them 
instincts  to  seek  refuge  from  the  weather  in  burrows,  in  hollow  trees,  in 
nests  or  tenements  which  they  build,  or  in  the  natural  caves. 

8.  She  has  also  given  them  a  clothing,  to  some,  of  feathers ;  to  some 
of  wool ;  to  some  of  hair ;  to  some  of  fur ;  and  her  operations  are  so 
wonderful,  that  these  coverings  become  thicker  in  the  fall  and  remain  so 
during  the  winter,  but  in  the  spring,  the  summer  coat  is  regained  and  re- 
mains till  fall. 

9.  To  the  swine,  however,  she  has  only  given  a  thin  coat  of  bristles, 
as  an  external  coat.    But  directly  within  the  skin  is  found  a  layer  of  fat, 
which  is  readily  formed,  and  becomes  very  thick  in  the  fall  of  the  year. 
This,  then,  must  be  the  protective  coat  of  the  swine.     There  are,  there- 
fore, two  kinds  of  protection  furnished  to  animals,  viz.,  an  internal  coat, 
and  an  external  coat. 

10.  To  most  animals  she  has  furnished  both,  in  a  greater  or  less  de- 
gree ;  to  some  but  one.     The  hog  can  hardly  be  said  to  have  any  ex- 
ternal coat.     Man,  frequently  compared  to  the  swine,  is  similar  in  this 
respect,  nature  furnishing  him  with  the  internal  coat  only,  which  in  case 
of  infants  is  usually  very  abundant,  and  if  not  too  abundant,  is  exceed- 
ingly favorable  to  their  welfare,  by  preserving  in  their  little  bodies,  with 
comparatively  large   surfaces,  the  small  amount  of  heat  produced  therein. 
Here  it  may  also  be  observed,  that  nature  has  given  the  young  of  ani- 
mals, which  are  lean,  an  instinct  to  come  to  the  body  of  the  parent  for 
heat ;  see  the  chicken  "  brooding "  under  the  wings  of  the  hen. 

11.  The  whale  has  also  a  thick  internal  covering.     The  water  in 
which  the  animal  lives  renders  it  impossible  for  him  to  be  supplied  with 
an  external  coat.      Some  other  kinds  of  fishes  have  no  such  internal 
coat.     Some  have  it.     The  reason  for  the  difference  will  be  found  in 
this.     It  is  necessary  for  the  whale  to  be  kept  warmer  than  the  fishes 
without  the  internal  coat.     They  are  warm  enough  if  they  are  a  little 
warmer  than  the  water  in  which  they  live.     Some  are  not  any  warmer 
than  the  surrounding  water,  and  if  the  water  be  warmed,  they  will  re- 
main cooler  than  the  water.     It  is  frequently  observed,  that  placing  a 
fish  globe  too  near  the  fire  kills  the  fish ;  the  reason  being,  that  tha 
water  is  kept  too  warm  for  their  health.    But  th«  whal«,  and  all  fish 


GENERAL  OBSERVATIONS.  245 

with  the  internal  covering  of  fat,  must  be  kept  much  warmer  than  the 
water  in  which  they  live. 

12.  It  seems,  therefore,  that  the  covering  of  an  animal  is  thick,  corres- 
ponding with  the  importance  that  it  should  be  kept  warm.     Therefore, 
animals  clothed  with  feathers  should  be  very  warm.     It  will  be  found 
that  the  lark  is  the  warmest  blooded  animal  of  any  known.     Its  natural 
temperature  is  about  117  degrees.     Therefore,  the  thick  deposit  of  fat, 
in  case  of  the  child,  shows  that  it  is  very  important  it  be  kept  warm, 
and  comparatively  with  after  years,  the  importance  of  taking  care  that 
it  be  kept  warm,  is  very  great.     In  the  first  place,  the  organs  of  the 
infant  are  so  little  developed,  it  is  doubtful  whether  it  can  perfectly 
perceive  sensations;  and  indeed,  it  is  doubtful  if  sensations  are  very 
perfectly  produced.     In  the  next  place,  if  it  perceive  unpleasant  sen- 
sations of  chilliness  or  heat,  it  has  not  the  power  of  telling  its  wants; 
it  can  only  cry,  which  too  frequently  is  misunderstood  to  signify  a  want 
of  food. 

13.  Most  animals  have  not  only  the  external  coat  thickened  in  the 
fall ;  but  it  is  a  thing  of  common  note,  that  all  animals  fatten  easily  in 
the  fall  of  the  year.     Man  notices  this  in  respect  to  himself.     It  may 
also  be  observed,  that  animals,  including  man,   "grow  thin"   in  the 
spring  of  the  year,  and  remain  so  during  the  summer ;  the  reason  of 
which  is  perfectly  obvious;  yet  many  would  desire  to  preserve  their 
"  plump  appearance "  in  summer  as  well  as  in  winter,  and  think  health 
must  be  failing,  when  they  perceive  their  weight  to  lessen,  and  consider 
this  one  reason  why  they  should  have  recourse  to  "  spring  medicines ;" 
all  which  ideas  are  evidently  wrong. 

14.  In  cold  regions  we  should  expect  to  find  the  internal  and  ex- 
ternal clothing  of  animals  very  thick  and  protective.     The  long  shaggy 
fur,  and  thick  coat  of  fat  possessed  by  the  polar  bear,  justifies  our  ex- 
pectations. 

15.  In  warm  regions,  on  the  other  hand,  we  would  expect  to  find 
animals  lean,  and  without  external  clothing.     At  first,  the  long  furry 
coat  of  the  tiger  might  disappoint  our  expectations,  but  one  other  con- 
sideration would  satisfy  our  minds  that  the  rule  is  of  universal  applica- 
tion, viz.,  the  colder  the  weather,  other  things  being  equal,  the  more 
protective  will  be  the  external  or  internal  clothing  of  any  animal  natu- 
rally exposed. 

16.  The  clothing  of  man  and  animals  is  usually  called  protective 
against  cold  ;  so,  also,  is  the  shelter  provided  for  animals.     In  common 
conversation  this  is  well  enough ;  but  such  language  is  not  strictly  correct, 


246  GENERAL  OBSERVATIONS. 

and  it  ia  injurious,  as  it  draws  off  the  mind  from  seeing  one  important 
practical  idea,  viz.,  clothing  and  shelter  protect  the  body  by  preventing 
heat  from  going  out  of  it.  There  is  no  danger  of  cold  coming  in.  Cold 
merely  means,  absence  of  heat,  so  when  heat  goes  out  of  the  body,  the 
body,  for  want  of  the  heat,  is  called  cold. 

17.  If  a  person,  when  cold,  retire  to  sleep  in  a  cold  chamber,  he  will 
wake  in  the  morning  not  only  warm  himself,  but  he  will  find  the  clothing 
warm.     He  must,  therefore,  have  produced  heat  within  himself,  tvhich 
the  clothing,  to  a  great  degree,  has  prevented  from  passing  off.     If  he 
load  the  bed  with  sufficient  clothing,  he  will  wake  and  find  himself  too 
warm  for  comfort ;  he  may  be  perspiring  freely.     This  shows  that  heat 
is  produced  in  his  body,  even  after  it  is  warm  enough  for  comfort.     It 
will  now  be  seen  that  the  quantity  of  clothing  upon  the  bed,  and  which 
man  or  animals  should  wear,  will  not  depend  merely  on  the  coldness  of 
the  weather,  but  also  on  the  amount  of  heat  produced.     For  it  is  evi- 
dent if  a  certain  temperature  is  to  be  preserved,  and  there  is  only  little 
heat  produced  in  the  body,  that  little  must  be  husbanded  very  scrupu- 
lously.    When,  therefore,  we  see  the  thick  coat  of  the  tiger,  an  inhabi- 
tant of  a  warm  climate,  we  can  infer  that  in  his  body  very  little  heat, 
indeed,  is  produced,  which,must  be  very  carefully  preserved. 

18.  When  we  next  inquire,  by  what  means  the  heat  is  produced  in 
the  body,  the  attention  will  be  directed  to  the  fact,  that  man  and  all  ani- 
mals eat  more  in  the  winter  than  in  the  summer ;  much  more  in  cold 
climates  than  in  warm.     Every  one  has  noticed  that  the  appetite  dimin- 
ishes in  the  spring  of  the  year ;  and  though  many  may  think  this  owing 
to  ill  health,  there  is  evidently  a  good  reason  why  it  should  be  so.     It 
will  also  be  noticed  that  the  appetite  is  not  as  good  in  the  warm  days  of 
winter,  as  in  the  cold.     It  will  be  noticed  that  the  colder  the  weather  is, 
the  more  do  animals  eat.     It  will  be  noticed  that  the  more  exposed  to 
the  cold  a  person  is,  the  more  does  he  eat  j  and  that  if  he  take  a  ride  of 
a  cold  winter's  day,  it  gives  a  keen  appetite.     It  is  evident,  therefore, 
that  the  food  we  eat  is  the  means  of  warming  us,  or  has  something  to  do 
with  it. 

19.  It  is  also  evident,  that  the  better  animals  are  protected  by  nature 
or  by  art,  either  in  respect  to  shelter  or  clothing,  external  or  internal, 
the  less  food  will  they  require.     The  better  stabled,  the  less  will  it  cost 
to  keep  animals :  a  blanket  upon  a  cow,  will  be  as  profitable  as  upon  a 
horse.     A  fat  animal,  will  eat  less  food  than  a  lean  one.     An  animal 
with  a  thick  coat  of  hair,  wool,  or  fur,  will  "winter"  at  less  expense 


GENERAL  OBSERVATIONS.  247 

than  otherwise.    A  swarm  of  bees  will  not  eat  so  much  of  their  honey 
if  their  hive  be  kept  in  a  proper  place,  as  they  will  if  it  be  exposed. 

20.  But  when  we  take  another  view  of  the  tiger,  it  is  found  that 
though  he  eats  plenty  of  food,  his  furry  coat  exhibits  that  only  a  little 
heat  is  produced  in  his  system.     It  will  then  be  inferred  that  the  kind 
of  food  that  an  animal  eats,  has  something  to  do  with  the  warming 
of  his  body.     If  we  notice,  we  shall  see  that  the  tiger  lives  upon  lean 
meat ;  and  if  the  experiment  be  tried  of  throwing  a  piece  of  lean  and 
fat  meat  into  the  cage  of  a  tiger,  he  will  be  seen  to  carefully  gnaw 
off  the  lean,  and  leave  the  fat.     The  polar  bear,  on  the  other  hand,  lives 
upon  fat  with  delight ;  for,  though  he  be  warmly  clothed  within  and 
without,  his  native  region  is  the  birthplace  of  the  iceberg,  and  he  re- 
quires much  food  of  a  kind  that  will  make  him  warm. 

21.  It  will  also  be  noticed,  that  man  is  inclined  to  live  upon  one 
kind  of  food  in  summer  and  another  kind  in  winter.     Buckwheat  cakes, 
with  an  accompaniment  of  syrup  and  butter,  are  highly  relished  in  win- 
ter, but  set  aside  in  warm  weather.     In  cold  climates  man  finds  the 
animals  which  he  uses  for  food,  fat ;  while  in  warm  climates,  they  are 
lean  :  there  also,  fruits  are  more  abundant,  while  in  cold  climates  almost 
his  only  food  consists  of  meat.     The  Esquimaux  drinks  the  oil  of  the 
whale  by  the  gallon.* 

22.  The  squirrels  also  are  plump  and  fat  in  the  fall  of  the  year,  when 
they  enter  their  holes ;  so  also  are  the  bears,  when  they  go  into  their 
winter  dens — but  in  the  spring  they  are  lean.     That  the  fat  is  used  on 
account  of  the  cold  weather,  is  evident  from  this ;  that  the  colder  the 
winter,  the  more  lean  are  all  such  animals  when  spring  comes.     Indeed, 
if  the  winter  be  very  cold  and  long,  bears  frequently  come  out  from  their 
dens  in  the  mountains  of  Russia  and  Switzerland,  and  driven  by  neces- 
sity for  food  to  keep  themselves  warm,  they  will  attack  even  man  whom 
they  otherwise  shun.     Bees  also  keep  themselves  warm  during  winter, 
by  the  use  of  honey.     Cows  and  other  such  animals  when  driven  by 
hunger  in  cold  weather,  "  browse  " — as  the  expression  is — that  is,  feed 
upon  the  tender  buds  of  trees.     These  contain  gum  in  abundance.     We 
are  told  also,  that  travellers  in  Arabia  supply  their  wants  while  passing 
from  one  village  or  city  to  another,  by  a  small  quantity  of  gum.     Gum  ia 


*  This,  when  fresh,  is  much  like  lard.  In  the  summers  of  the  tem- 
perate zone,  vegetables  are  abundant ;  if  the  weather  be  hot,  they  will 
also  be  more  watery  ;  while,  if  the  weather  be  cold,  vegetation  is  lest 
luxuriant  and  more  solid. 


248  GENERAL  OBSERVATIONS. 

also  frequently  given  to  the  sick,  as  a  kind  of  food  very  easily  digested 
and  very  wholesome. 

23.  The  kind  of  food  which  many,  indeed  most  animals  are  fattened 
upon,  indicates  that  starch  is  well  adapted  as  food  to  warm  the  system  ; 
for  the  chief  ingredient  which  renders  grains,  potatoes,  &c.,  good  to  fat- 
ten animals,  is  the   starch  they  contain.     An  experiment  of  throwing 
starch,  fat,  gum,  sugar  (for  sugar  may  be  taken  to  represent  that  class 
of  food  to  which  honey  belongs),  into  the  fire,  will  convince  any  one, 
that  under  certain  circumstances  they  can  produce  much  heat 

24.  But  upon  further  inquiry  it  is  ascertained,  that  though  an  animal 
be  well-fed,  he  will  not  be  kept  warm  if  he  be  placed  in  a  cold  situation 
and  compelled  to  breathe  bad  air ;  or  if  a  band  be  tied  about  his-  chest,  so 
that  he  does  not  receive  a  sufficient  supply  of  air,  even  if  it  be  good. 
This  would  signify  that  pure  air,  and  a  good  supply  of  it,  are  essential  to 
warmth  of  the  body — and  thorough  examination  proves  this ;  for  those 
who  labor  in  close  apartments,  are  very  liable  to  complain  of  cold  and 
be  "  pinched  "  with  it,  when  they  go  out.     In  cold  weather,  also,  fires 
will  burn   more  briskly  than  in  warm.     The  air   is  adapted,  in  cold 
weather,  to  the  production  of  more  heat  than  in  summer. 

25.  It  is  also  found,  that  there  is  great  complaint  of  suffering  among 
those  who  restrain  the  action  of  the  chest  by  tight  dresses,  or  whose 
lungs,  on  account  of  disease,  cannot  receive  as  much  air  as  is  necessary 
for  warming  the  body.      Those  animals,  also,  which  are  most  warm- 
blooded, receive  the  most  air  in  proportion  to  their  size.     Birds  receive  a 
great  deal  of  air ;  for  it  not  only  passes  into  their  lungs,  but  into  their 
bones,  and  into  various  apartments  of  their  bodies.     The  cold-blooded 
fishes  are  satisfied  with  what  little  air  they  obtain  from  the  water  ;  but 
the  warm-blooded  whale  is  furnished  with  immense   lungs,  which  he 
comes  to  the  surface  of  the  ocean  to  fill  with  the  pure  air. 

26.  The  extremities  of  the  body  are  of  a  lower  natural  temperature 
than  the  central  parts  ->  the  temperature  rising  as  we  pass  from  the  sur- 
face of  the  body  towards  the  heart,  where  it  is  found  that  all  the  blood 
in  the  body  is  continually  flowing  out  to  the  lungs,  from  which  it  quickly 
returns  a  little  warmer  than  it  was.     Again,  when  a  person  begins  to 
take  exercise,  he  begins  to  grow  warmer,  and  at  the  same  time  he  no- 
tices that  the  blood  moves  and  he  breathes  more  rapidly  ;  from  which  it 
follows  that  when  he  exercises,  more  air  acts  on  the  blood  in  a  given 
length  of  time,  than  when  he  is  quiet.     When  the  ah-  is  blown  against 
coals,  or  when   a   draught  acts   upon  the  fire,  it  burns  more  rapidly 


GENERAL  OBSERVATIONS.  249 

and  causes  more  heat.     It  might  be  inferred  that  the  greater  the  quantity 
of  air  acting  on  the  blood  in  the  lungs,  the  warmer  would  a  person  be. 

27.  Thus  it  may  be  considered  as  certain,  that  the  heat  of  the  body 
is  produced  by  the  food  on  the  one  hand,  and  by  the  air  on  the  other. 
But  in  the  next  place,  how  shall  it  be  distributed  through  the  body?    This 
could  easily  be  accomplished  by  having  a  fluid  continually  moving  through 
every  part  of  the  body,  for  if  any  part  were  warm  the  fluid  would  be- 
come warm,  and  if  any  part  were  cold  the  fluid  would  warm  it. 

28.  But  it  is  evident,  that  if  the  heat  of  the  body  should  >e  contin- 
ually produced,  the  body  would  grow  too  warm,  and  much  harm  would 
follow,  as  in  case  of  fever.     In  this  case  it  might  be  observed  that  the 
skin  was  dry,  harsh,  and  hot,  the  brain  delirious,  &c.     But  as  soon 
as  a  gentle  perspiration  breaks  out,  the  skin  becomes  cool  and  flexible, 
the  delirium  subsides,  and  the  doctor  expresses  hopes  of  his  patient.     In 
warm  weather  a  person  perspires  freely,  while  in  cold  weather,  perspi- 
ration ceases.    An  animal  that  sweats  freely  suffers  but  little  from  heat. 
The  horse,  intended  by  nature  for  active  exercise  and  to  produce  much 
heat,  sweats,  and  bears  hard  driving  in  summer  weather  while  he  sweats, 
but  if  the  skin  become  dry,  he  will  be  injured  except  cooled  by  artificial 
means.* 

The  ox  is  easily  killed, "  melted"  as  it  is  termed,  by  over-exercise 
on  a  hot  day.  That  animal  does  not  sweat  except  by  its  tongue,  which 
is  kept  moisf  and  thrust  from  the  mouth,  as  it  will  be  by  the  horse  if  the 
case  be  extreme. 

29.  The  dog  is  easily  killed  by  over-exercise  in  hot  weather,  espe- 
cially if  fed  upon  food  that  tends  to  produce  heat  and  fat,  while  if  he  be 
fed  upon  the  tiger's  food  and  kept  lean,  there  is  no  danger.     The  dog  is 
remarkable  for  "  lolling,"  as  the  term  is,  and  also  for  panting,  which  is 
merely  a  fanning  operation.     The  air  which  he  draws  into  his  mouth, 
does  not  pass  deeply  into  his  lungs  so  as  to  produce  much  heat,  but  is 
merely  drawn  in  and  thrown  out,  to  assist  in  cooling  him  by  carrying 
away  the  moisture  more  rapidly  from  the  tongue. 

30.  The  effect  of  the  perspiration  in  cooling  the  body  is  evidently  the 
same  as  the  effect  of  the  water  thrown  upon  the  floor  in  summer :  the 


*  If  a  horse  driven  upon  the  road  on  a  hot  day,  be  observed  to  be- 
come dry,  which  intense  heat  will  frequently  cause  (it  seeming  to  produce 
such  a  feverish  state  of  the  skin  that  it  cannot  sweat),  it  will  greatly  re- 
lieve the  animal  to  dip  some  twigs  with  leaves  upon  them  in  water,  and 
•prinkle  the  animal  pretty  effectually.  It  cools  him. 

n* 


250  GENERAL  OBSERVATIONS. 

water  and  the  perspiration  evaporate  and  produce  coolness.  In  the 
Indies,  before  the  introduction  of  ice,  the  people  were  in  the  habit  of 
wrapping  wet  cloths  around  jugs  filled  with  drink,  and  putting  them  in  the 
sun,  that  the  water  might  evaporate  easily  from  the  cloths  and  produce 
coolness  of  the  drink.  It  is  evident,  then,  that  the  perspiration  is  for  the 
purpose  of  keeping  the  body  properly  cool. 

31.  But  how  shall  the  perspiration  continue  to  ooze  out  of  the  body 
without  drink  be  taken  to  supply  it  ?     It  will  also  be  observed,  that  a 
person  drinks  more  in  warm  weather  than  in  cold  ;  those  who  work  in 
warm  exposures,  for  instance  glass-blowers,  perspire  very  much,  and 
drink  very  freely.     One  office,  therefore,  of  the  drink,  must  be  to  cool 
the  body,  not  merely  by  the  coolness  when  swallowed,  but  by  passing 
through  the  skin  in  the  form  of  perspiration  and  evaporating  from  the 
body. 

32.  It  might  be  asked,  how  shall  the  water  drank  through  the  mouth 
reach  the  skin  ?    But  by  passing  into  a  set  of  vessels  or  tubes,  which  lead 
into  every  part  of  the  body,  it  could  be  distributed  to  the  skin  and  thrown 
out,  as  the  system  might  require. 

33.  To  preserve  the  temperature  of  the  body,  these  several  things 
then  will  be  required :  1st.  Food  of  a  proper  quality  and  in  proper  quan- 
tity. 2d.  An  apparatus  to  prepare  the  food  to  fulfil  its  purpose  in  respect 
to  producing  heat.  3d.  Air  of  proper  quality  and  in  proper  quantity.  4th. 
An  apparatus  in  which  it  may  be  received  and  caused  to  fulfil  its  duties. 
5th.  Drink  and  an  apparatus  for  its  reception.  6th.  An  organ  through 
which  it  may  be  perspired.   7th.  A  grand  apparatus  of  circulation  to 
serve  the  various  purposes  of  carrying  the  food  and  air,  if  need  be,  to 
where  they  are  needed  to  produce  heat,  to  distribute  the  heat,  and  to  dis- 
tribute the  drink  to  the  perspiring  apparatus. 

The  Nourishing  of  the  Body. 

34.  This  is  necessary  on  account  of  the  continual  wear  of  the  system, 
and  in  early  life  on  account  of  the  daily  increase  from  infancy  to  man- 
hood in  the  size  of  the  organs.     The  amount  of  nourishing  to  be  done 
will  therefore  depend  on  the  exercise  of  the  various  organs  of  the  body, 
(for  on  their  exercise  depend  the  amount  of  their  wear  and  decomposition) 
and  on  the  rapidity  with  which  the  body  is  growing. 

35.  It  will  be  noticed,  that  the  more  a  person  exercises,  the  more  will 
he  eat    The  laboring  man  has  a  heartier  appetite  than  the  professional 


GENERAL  OBSERVATIONS.  251 

man.*  The  animal  that  works  hard  has  a  keener  appetite  than  the  idle 
animal.  When  a  child  is  growing  rapidly  it  requires  much  food  and  has 
a  hearty  appetite. 

36.  It  is  therefore  evident  that  the  food  affords  nourishment,  and  if  we 
examine  the  tiger  again,  we  shall  see  that  he  is  very  strong,  carrying 
off  an  ox  with  ease,  it  is  said.      If  lean  meat  be  little  adapted  to  keep 
him  warm,  it  is  adapted  to  make  him  strong.     The  farmer  finds,  also, 
that  buttermilk  is  adapted  to  his  use,  in  the  midst  of  the  summer  heats. 

37.  If  we  examine  how  this  is,  we  shall  immediately  conclude  that 
the  food  which  is  to  nourish  the  body  must  contain  the  ingredients  of 
which  the  body  is  composed.      That  milk  -contains  these  ingredients  is 
certai.i,  for  we  see  all  parts  of  an  animal  to  be  formed  of  milk.     A  calf, 
for  instance,  eating  nothing  but  milk,  grows  large  and  strong.     The  milk 
must  contain  all  the  substances  necessary  to  form  the  bones,  the  nerves, 
the  brain,  and  every  part  of  the  animal.     So  a  chicken  comes  out  of  the 
shell,  its  bones,  its  flesh,  and  all  its  parts  being  formed  from  the  contents 
of  the  shell.     Whence  eggs  must  be  very  nourishing.t 

38.  It  may  be  proper  in  this  place  to  mention,  in  further  explanation 
of  this  matter,  that  the  whole  world  is  composed  of  some  fifty-six  differ- 
ent substances',  some  of  which  exist  in  very  small  quantities.     Water  is 
composed  of  two  of  these  substances,  called  oxygen  and  hydrogen.     One 
other  substance  called  carbon,  added  to  oxygen  and  hydrogen,  forms  fat. 
The  proportions  of  the  three  substances  being  varied  a  little,  sugar  ia 
formed ;  being  varied  again,  starch  or  gum  will  be  formed.     Thus  all  the 
various  things  with  which  we  are  acquainted,  are  made  up  of  some  few 
things  imited  in  certain  proportions.     In  the  human  body,  thirteen  differ- 
ent substances  are  always  found.    So  many  are  necessary.     Some  of  them 

*  This  tends  to  show  that  fatigue  after  the  use  of  the  muscles  is  owing 
to  the  state  of  the  muscles,  and  not  merely  to  the  state  of  the  nervous 
system.  For  without  doubt  the  professional  man  uses  the  nervous 
system  more  in  thinking,  than  the  laboring  man  in  the  same  length  of 
time ;  but  the  laboring  man  requires  more  food  to  replace  the  large 
amount  of  his  muscles  which  has  become  unfit  for  use  during  his  labors. 

t  It  seems  a  fortunate  thing  that  eggs  are  plenty  in  the  commence 
ment  of  summer,  that  very  time  when  food  is  required  which  shall  be 
nourishing  and  not  warming ;  and  that  the  egg  does  not  contain  much 
substance  adapted  to  the  latter  purpose  is  evident,  from  its  being  necessa- 
ry for  the  hen  to  keep  the  eggs  warm  with  the  heat  of  her  own  body. 
The  chick  in  the  egg  is  not  able  to  keep  itself  warm,  and  after  it  is 
hatched,  it  is  necessary  for  some  time  that  it  obtain  a  great  part  of  its 
heat  from  an  external  source. 


252  GENERAL  OBSERVATIONS. 

are  in  very  small  quantities,  but  they  are  always  present,  and  the  body 
cannot  exist  without  every  one  of  the  thirteen,  composing  it.  There  are 
usually  nineteen  different  substances,  but  of  the  last  six  sometimes  one 
and  sometimes  another  is  wanting.  If,  therefore,  a  person  growing 
should  receive  but  twelve  out  of  the  thirteen  necessary  substances,  he 
could  not  live  long.  Hence  nourishment  must  contain  the  necessary 
constituents  of  the  body — not  that  every  portion  of  nourishment  must 
contain  each  of  the  thirteen,  for  as  only -a  small  quantity  of  some  of  the 
thirteen  is  required,  if  they  are  used  occasionally  it  is  sufficient.  More 
upon  this  point  hereafter. 

39.  The  food  for  nourishing  the  body  appears  so  unlike,  in  many  in- 
stances, the  various  parts  it  is  to  nourish",  it  is  evident  it  must  undergo 
some  process  of  preparation.     But  in  the  next  place  it  is  evident  it  must 
be  carried  to  every  part  of  the  body  where  it  will  be  required.     To  ac- 
complish this,  nothing  seems  more  desirable  than  to  have  it  become  part 
of  the  fluid  which  is  moving  through  every  portion  of  the  body.     Nothing 
therefore  is  required  for  distributing  it,  in  addition  to  the  apparatus  neces- 
sary for  preserving  the  temperature  of  the  body. 

The  Process  of  Excretion. 

40.  This  is  rendered  necessary  by  the  constant  action  which  is  taking 
place  in  the  various  organs,  on  account  of  which  parts  of  them  become 
unfit  for  use,  or  are  decomposed,  as  the  expression  is.      It  is  easy  to  see 
that  three  things  may  be  true  of  the  substance  decomposed  in  the  organs : 
1st.  The  whole  or  part  of  it  may  be  of  use  in  nourishing,  that  is,  supply- 
ing the  wants  of  some  other  part  of  the  body.     2d.  It  may  be  of  use  in 
the  production  of  heat ;   and  the  increased  heat  attendant  upon  taking 
exercise  of  any  part,  points  very  strongly  that  way.     3d.  A  part  or  all 
of  it  must  be  cast  out  of  the  body  as  unfit  to  fulfil  any  duty  therein,  hav- 
ing performed  the  office  for  which  it  was  designed.     And  sooner  or  later 
this  is  what  must  take  place,  in  order  that  we  may  account  for  the  large 
amount  of  food  which  persons  every  day  use. 

41.  The  first  thing  necessary,  however,  in  regard  to  this  substance 
thus  become  unfit  for  use,  is,  that  it  be  removed  from  the  organs  in  which 
it  is  unfitted  any  longer  to  serve  a  useful  purpose  ;  for  if  it  remain,  it  will 
only  clog  their  action  and  produce  unpleasant  sensations.      This  can  be 
accomplished  in  the  easiest  manner,  by  having  the  substance  pass  into 
the  vessels  before  shown  to  be  required,  and  become  a  part  of  the  fluid 
that  they  contain. 


GENERAL  OBSERVATIONS.  253 

42.  The  second  thing  neceasary  is,  to  have  this  substance  subjected 
to  such  an  action,  that  if  it  contain  any  substance  profitable  in  any  part 
of  the  body,  or  adapted  to  produce  heat,  it  may  be  retained,  and  the  re- 
mainder cast  out  of  the  system. 

43.  In  the  duty  of  excretion,  therefore,  one  or  more  organs  will  be 
required,  through  which  the  fluid  containing  the  decomposed  substance 
may  pass,  and  be  acted  upon  as  the  case  may  require. 

The  Nervous  System  of  Organic  Life. 

44.  But  when  there  is  much  exercise,  much  substance  will  be  decom- 
posed ;  there  will  then  be  required  increased  action  of  the  excreting  ap- 
paratus, the  nourishing  process  must  take  place  more  rapidly,  a  greater 
appetite  will  be  necessary,  and  the  circulation  of  the  fluid  containing  the 
decomposed  substance  and  the  nutriment  must  be  hurried.     So  also  if  a 
person  be  exposed  to  great  heat  or  cold,  the  action  of  the  respective 
organs  having  duties  to  perform  in  reference  thereto,  must  be  increased 
or  diminished. 

45.  To  accomplish  what  will  be  necessary  in  these  respects,  a  ner- 
vous system  will  be  required,  which  shall  bind,  so  to  speak,  all  parts  into 
one.     This  nervous  system  must  consist  of  one  or  more  centres,  upon 
which  the  states  of  any  and  all  the  organs  of  the  body  shall  act,  and 
from  which  effects  shall  be  produced  on  any  or  all  parts  of  the  body,  as 
the  necessity  of  the  case  shall  require. 

46.  From  these  various  organs  of  the  second  class  there  must  also  be 
communication  with  the  mind,  upon  which  at  times  they  can  produce 
effects,  that  its  assistance  may  be  given  in  the  fulfilment  of  duties  which 
could  not  otherwise  be  accomplished.     But  that  every  act  of  these  organs 
should  be  brought  before  the  mind  would  not  be  at  all  proper,  for  as  the 
processes  referred  to  in  the  previous  paragraphs  of  this  book  are  constantly 
taking  place,  the  attention  of  the  mind  would  be  so  occupied  that  it  could 
not  attend  to  its  legitimate  business.      It  is  like  the  arrangements  in  a 
grand  manufacturing  establishment ;   the  mind  has  a  general  oversight, 
and  constantly  exerts  an  unseen  influence,  but  is  only  called  on  to  give 
particular  attention  here  or  there  on  especial  occasions  ;  but  is  left  to  do 
the  "  out-door  business  of  the  concern  " — the  thinking,  the  "  buying  and 
selling,"  &c. 

The  divisions  which  will  be  made  in  the  second  book  we 
now  evident. 


CHAPTER  L 

THE  DIGESTIVE    OEGANS. 


47.  These  receive  the  food  and  drink,  and  through  these  the  drink 
without  preparation,  and  the  food  after  being  subjected  to  certain  pro- 
cesses, pass  into  the  bloodvessels.  The  action  of  the  digestive  organs 
upon  the  drink  is,  therefore,  very  simple ;  but  the  food  is  submitted  to 
three  different  operations  before  passing  into  the  bloodvessels.  The  first 
takes  place  in  the  mouth,  the  second  in  the  stomach,  the  third  in  the 
second  stomach. 


SECTION  1. — The  Mouth. 

48.  This  may  be  divided  into  the  front  mouth  and  the 
back  mouth  or  upper  part  of  the  throat,  the  part  commenc- 
ing at  the  back  part  of  the  tongue  and  leading  above  into 
the  nose,  and  below  into  the  gullet,  meat-pipe,  swallow  or 
oesophagus,  and  into  the  windpipe ;  it  is  technically  called 
the  pharynx;. 

49.  The  front  mouth'  every  person  understands,  it  being 
so  readily  presented  to  view.     In  this  the  food  is  subjected 
merely  to  a  mechanical  process.     It  is  ground,  masticated 
or  chewed,  and  mixed  with  the  saliva  or  spittle.     The  same 
process  might  be  accomplished  in  a  mortar  if  a  proper  portion 
of  food  and  saliva  were  ground  therein. 

It  is  a  very  important  process ;  for  it  is  found  that  if  the  food  be 
swallowed  in  haste,  being  but  half  masticated,  dyspepsia  soon  follows ; 
it  is  also  found  very  difficult  to  fatten  animals  which  have  lost  their 
teeth,  without  very  soft  food  be  given  to  them.  That  it  is  important 


SEC.  1.]  THE  MOUTH.  255 

saliva  should  be  mixed  Math  food,  is  evident  from  the  provisions  of  nature. 
The  young  of  all  animals  which  yield  milk,  obtain  their  food  by  drawing 
or  sucking  it  into  their  mouth,  by  which  means  a  large  quantity  of  saliva 
is  mingled  with  the  food.  Chewing  the  food  has  been  so  arranged  by 
nature  as  to  cause  saliva  to  flow  into  the  mouth  in  large  quantities.  It 
has  also  been  found  in  certain  diseases,  where  the  saliva  has  not  been 
formed,  or  if  formed,  lost  by  flowing  through  an  opening  in  the  cheek, 
that  digestion  of  the  food  in  the  stomach  did  not  take  place  well.  Dr. 
Beaumont  found  also,  that  if  food,  unmixed  with  saliva,  were  placed  in 
the  stomach,  it  did  not  digest  well.  Persons  who  drink  milk,  often 
notice  that  it  does  not  "  set  well  upon  the  stomach."  All  nations,  so 
far  as  I  can  learn,  with  milk  eat  bread  or  some  like  substance,  which, 
by  requiring  to  be  chewed,  may  supply  the  proper  quantity  of  saliva ; 
they  having  learned  by  experience  that  this  is  better.  It  is  therefore  to 
be  inferred,  and  held  as  a  golden  rule,  that  a  child  should  never 
be  fed  with  a  spoon,  but  caused  to  draw  the  food  into  its  mouth  by 
sucking,  according  to  the  intentions  of  nature. 

50.  The  mouth  may,  therefore,  be  considered  under  four 
divisions :  the  teeth,  the  skin  lining  the  mouth,  the  salivary 
apparatus,  the  muscles  which  move  the  jaws  and  bring  the 
food  under  the  teeth,  and  which,  after  the  food  is  prepared, 
pass  it  into  the  back  mouth. 

A.  The  Teeth. 

51.  These  are  firmly  placed  in  the  jaw  by  the  parts 
called  the  roots  or  fangs.     Another  portion  of  the  tooth  is 
covered  by  the  fleshy  gum,  the  remaining  portion  projecting 
into  the  mouth,  is  called  the  crown  of  the  tooth. 

52.  The  outside  of  the  crown  is  a  hard,  thin  shell,  called 
the  enamel,  covering  the  part  within,  as  the  thimble  covers 
the  end  of  the  finger.     The  inner  part  of  the  tooth  and  the 
fangs,  except  a  central  canal,  (Fig.  86),  is  composed,  in  fact, 
of  two  kinds  of  substance,  one  called  the  cortical  and  the  other 
the  ivory  of  the  tooth;  but  usually  the  distinction  is  not 
noticed,  and  the  whole  is  called  the  ivory.     It  is  not  as  hard 
as  the  enamel. 


256 


THE  DIGESTIVE  ORGANS. 
Fig.  86. 


[CHAP,  x. 


Fig.  86.— A,  Perpendicular  section  of  a  molar,  magnified  four  diameters.  1,  Ivory 
with  wavy  tubes,  the  openings  of  which  are  seen  at  2,  the  canal  for  pulp,  central  nerve, 
&c.  3,  Is  called  the  cortical  portion,  and  forms  the  outside  of  the  fang.  4,  Enamel 
worn  away  at  the  summit  of  the  tooth.  B,  A  greatly  magnified  view  of  a  section 
across  the  tubes. 


53.  The  enamel  is  destitute  of  nerves,  and  of  course 
never  causes  any  sensations.     Jn  the  ivory  of  the  tooth,  there 
must  be  a  great  multitude  of  nerves ;  it  is  so  very  sensitive 
at  times. 

Whether  these  are  branches  of  the  nerves  found  in  the  central  canal 
of  the  tooth,  and  called  by  way  of  distinction,  the  nerve  of  the  tooth,  or 
are  branches  of  nerves  entering  the  tooth  from  the  outside,  is  uncertain. 

54.  There  is  a  delicate  skin  covering  the  fang  and  neck 


SEC.  l.J  THE  MOUTH.  257 

of  the  tooth.     This,  when  diseased,  causes  very  acute  pain 
if  touched  ever  so  gently. 

55.  The  use  of  the  enamel  is  to  preserve  the  internal  part  of  the 
tooth  from  exposure,  for  as  soon  as  the  air,  the  fluids  of  the  mouth,  or 
the  food  or  drink,  act  on  the  inner  portion  of  the  tooth,  they  cause  it  to 
decay.     The  enamel  has,  therefore,  been  made  hard  that  it  may  not  be 
easily  worn  away,  but  on  this  account  it  is  easily  cracked  by  hot  or  cold 
articles  of  food  or  drink  ;  for  as  a  cold  tumbler  will  crack  if  put  in  hot 
water,  because  the  heat  swells  the  outside  of  the  tumbler  before  it  has 
time  to  act  on  the  inside,  and  as  a  warm  -  tumbler  cracks  when  put  in 
cold  water,  so  will  high  and  low  temperatures  act  on  the  outside  of  the 
tooth  before  they  do  on  the  inside.     If  the  teeth  be  examined,  in  many 
persons  the  enamel  will  be  found  full  of  cracks,  looking  like  a  "glaze- 
cracked  plate,"  or  other  articles. 

56.  Through  these  cracks  substances  find  their  way  to  the  part  within, 
and  before  a  person  is  aware  that  decay  is  begun,  the  tooth  is  a  "  mere 
shell,"  viz  ,  nothing  but  the  enamel  is  left.     Very  hot  or  cold  drinks, 
iced  waters,  especially  when  preceded   by  a  cup  of  hot  tea  or  coffee, 
iced  food,  iced  creams,  iced  desserts,  are  not  only  unnatural,  but  must  be 
very  injurious  to  the  teeth.     Eating  snow,  sucking  icicles,  &c.,  should 
be  avoided. 

57.  The  hardness  of  the  enamel  is  not  only  observed  to 
differ  in  different  persons,  but  in  the  different  teeth  of  the 
same   person.      The  color  of  the  enamel   is   different;    it 
crumbles  very  easily  in  case  of  some  of  the  teeth,  slivers  off 
in  case  of  others,  while  in  other  teeth  of  the  same  person, 
the  enamel  is  solid,  good  colored,  and  enduring. 

It  will  also  be  noticed,  that  teeth  grow  in  pairs,  and  that  the  appear- 
ance of  the  teeth  in  the  same  pairs  is  similar.  If  one  tooth  of  the  pair 
decay,  the  other  will  soon  follow,  showing  that  the  same  causes  which 
operate  on  one  injuriously,  act  in  the  same  manner  upon  the  other ;  that, 
therefore,  as  the  teeth  were  made  at  the  same  time,  so  they  were  made 
alike. 

58.  There  are  evidently  two  things  which  would  affect 
injuriously  the  formation  of  teeth ;  disease  of  the  apparatus 
forming  the  teeth,  and  a  want  of  proper  material  from  which 
to  form  them. 


258  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

Disease  of  the  apparatus  forming  the  tooth  is  found  to  exhibit  itself 
most  usually  in  the  form  of  the  tooth,  which  will  have  a  "ridgy"  or 
"  wavy"  that  is,  an  uneven  surface,  while  a  want  of  proper  material 
would  be  naturally  exhibited  in  the  too  great  softness  of  the  tooth,  or 
its  tendency  to  crumble,  &c.  That  such  a  state  would  frequently  be 
produced  is  only  what,  would  be  expected  by  the  educated  person,  who 
sees  the  mother  setting  aside  the  perfect  milk,  containing  all  the  ingre- 
dients to  form  the  teeth  and  every  other  part  in  a  proper  manner,  and 
feeding  her  child  upon  "  pap"  and  like  substance,  in  the  composition  of 
which,  some  of  the  most  important  ingredients  of  the  teeth  are  entirely 
wanting. 

59.  But  though  the  enamel  was  intended  by  nature  to  be 
hard,  it  yet  was  intended  in  man  to  be  used  on  food  much 
softer  than  itself,  for  it  is  to  last  an  entire  life-time. 

The  teeth  of  the  squirrel  are  continually  growing  at  the  roots,  he  may 
therefore  gnaw  the  hard  shell  of  the  nut  without  danger.  But  the  boy 
should  be  warned  against  cracking  nuts  between  his  teeth,  or  biting  pins, 
or  breaking  hard  substances  with  the  teeth,  or  prying  upon  the  teeth  with 
any  thing  hard,  like  a  knife.  The  girl  and  lady  who  care  either  for  the 
beauty  or  health,  arising  from  preserved  teeth,  should  be  careful  not  to 
bite  hooks  or  eyes,  or  bite  off  threads  with  the  teeth,  as  there  is  danger, 
especially  if  a  tooth  happen  to  be  of  a  crumbly  character,  as  is  frequently 
the  case  with  the  teeth  of  ladies. 

60.  As  the  enamel  of  the  teeth  is  so  liable  to  become  cracked,  it  is 
exceedingly  important  that  the  teeth  be  kept  clean :  for  bits  of  food,  &c., 
being  allowed  to  remain  about  the  tooth  and  decay,  will  produce  acids, 
which  "  soaking,"  through  the  cracks  of  the  enamel,  will  exert  an  injurious 
influence  upon  the  ivory  of  the  teeth.     Many  recommend  to  wash  the 
teeth  after  each  repast,  but  they  should  be  thoroughly  cleansed  twice  per 
day,  on  rising  in  the  morning  and  retiring  at  night,  the  mouth  being  not 
only  rinsed  out,  but  the  teeth  brushed  above  and  below  as  well  within  as 
without,  and  the  brush  should  be  carried  up  and  down  as  well  as  across 
the  teeth. 

61.  If  the  teeth  are  not  frequently  brushed,  not  only  do  substances 
from  the  food  remain  about  the  teeth,  but  a  substance  from  the  fluids  of 
the  rnouth  is  apt  to  deposit  and  harden  on  the  teeth.     It  is  called  tartar, 
and  seems  almost  as  hard  as  bone  in  some  cases.     It  is  of  a  brown  or 
black  color,  and  besides  giving  a  very  bad  appearance  to  the  teeth,  tends 
to  work  down  beneath  the  gum  and  loosen  the  teeth  in  their  sockets. 


SEC.  1.]  THE  MOUTH.  259 

producing  also  a  very  undesirable  red,  swollen  and  spongy  appearance 
of  the  gums. 

62.  If  the  tartar  have  formed  unawares  to  a  person,  he  should  have 
it  immediately  removed.     If  it  have  caused  the  gums  to  be  diseased, 
they  should  be  freely  washed  with  cold  water  and  gently  brushed  with 
a  soft  brush.*     If  a  tooth  have  begun  to  decay,  it  should  be  attended  to 
at  once.     The  decayed  portion  must  be  entirely  removed  and  the  place 
filled  with  gold,  if  possible  ;  but  if  the  tooth  be  "  too  far  gone,"  the  author 
can  testify  from  ten  years'  experience  with  one  tooth,  to  the  wisdom  of 
having  the  cavity  filled  with  a  composition  made  by  the  dentists.     If  the 
tooth  can  neither  be  filled  nor  pulled,  a  little  pulverized  charcoal  held  in 
the  mouth  several  times  per  day,  will  somewhat  correct  the  bad  breath 
arising  from  decayed  teeth. 

63.  If  the  gums  remain  spongy  for  several  weeks  after  all  the  tartar 
has  been  removed  from  them,  and  they  have  been  repeatedly  washed 
with  water,  the  attention  of  the  physician  had  better- be  invited,  as  dis- 
ease of  the  stomach  and  its  connections  is  very  frequently  indicated  by 
the  appearance  of  the  gums. 

64.  Tobacco  is  sometimes  said  to  prevent  the  teeth  from  aching  and 
decaying.     It  cannot  do  the  last,  but  on  the  other  hand,  dentists  testify 
that  men  using  tobacco  are  more  troubled  with  decayed  teeth  than  those 
who  do  not  use  it.     It  can  do  the  first,  by  producing  such  a  state  of 
the  nerves  that  they  have  not  the  power  to  produce  sensations,  but  the 
tooth   continues   to   decay   if  the  nerve   do   not   give   warning  of  it. 
Therefore  the  tobacco  is  doubly  injurious,  it  increases  the  decay  of  the 
teeth,  while  at  the  same  time  it  does  not  allow  its  ravages  to  be  made 
known  to  the  mind. 

65.  The  teeth  are  thirty-two  in  the  adult ;  in  front,  four 
above  and  four  below  are  called  incisors,  or  cutting  teeth. 
Back  of  these,  one  above  and  below  on  each  side  are  called 
cuspid,  (spear  or  one-pointed,)  canine  or  dog  teeth.  Back  of 
these  upon  either  side,  two  above  and  below,  are  called  bicus- 
pid, from  having  two  points.  Three  on  each  side,  above  and 
below,  are  called  the  grinders,  from  their  use ;  and  one  of  these 

*  Indeed  a  softish  rather  than  a  hard  brush  is  preferable  for  any 


260 


THE  DIGESTIVE  ORGANS. 


[CHAP.  i. 


upon  each  side  above  and  below,  farthest  back,  from  not  ap- 
pearing till  between  the  years  of  15  and  25,  is  called  the 
wisdom  tooth  (Fig.  87). 

Fig.  87. 


Fig.  87.— 1, 2,  Incisors.-3,  Cuspid.-4, 5,  Bicuspid.-6, 7,  Molars.-8,  Wisdom. 

66.  These  take  the  -place  of  the  first  set,  though  larger  and  more 
numerous,  the  jaw  having  "  grown."  The  first  set  usually  disappears  be- 
fore the  appearance  of  the  second.  But  sometimes  a  tooth  of  the  first 
set  is  allowed  to  retain  its  place,  and  the  tooth  of  the  second  set  is  obliged 
to  appear  on  one  side  or  the  other  of  its  true  place,  disfiguring  a  person 
or  injuring  his  speech.  A  first  tooth  should  always  be  "  pulled"  in  sea- 
son. The  position  which  the  first  teeth  occupy  is  not  of  consequence,  nor  is 
the^  position  of  the  second  teeth,  provided  they  be  upon  the  ground  which 
they  ought  to  occupy.  That  is,  if  they  be  turned  to  one  side  or  the 
other,  it  is  not  of  much  moment,  for  very  frequently  the  jaw  has  not  en- 
larged sufficiently  to  allow  all  the  second  teeth  to  make  their  appearance 
in  due  season  and  in  an  even  manner ;  but  as  the  jaw  enlarges,  they 
will  become  even  and  properly  adjusted,  or  if  they  do  not,  and  there  be 
room  for  the  adjustment,  the  dentist  can  easily  by  springs,  &c.,  move 
the  teeth  till  they  are  right.  If  the  jaw  do  not  become  large  enough  for 
the  teeth,  one  tooth  can  be  drawn,  and  this  will  give  room  for  the  rest. 


SEC.  1.]  THE  MOUTH.  261 

It  is  now  seen  why  the  wisdom  teeth  appear  so  late  ;  there  is  not  room 
for  them  in  the  mouth  till  maturer  years. 

67.  The  second  set  of  teeth  begins  to  form  a  long  time 
before  the  first  ones  "  become  loose ;"  in  the  earliest  infancy 
their  formation  is  progressing. 

Hence  the  material  for  the  second  set  of  teeth  must  be  furnished  to 
the  babe  even,  that  their  foundation  may  be  good 

B.   The  Lining  of  the  Mouth. 

68.  This  is  very  much  like  the  external  covering  of  the 
body,  and  by  some  is  considered  a  continuation  of  it.     It  is 
composed  of  two  layers ;   the  external  is  called  epithelium, 
and  corresponds  to  the  external  layer  of  the  skin  (the  cuticle); 
but  is  much  thinner  and  more  delicate.     In  the  lining  of  the 
mouth  there  is  no  coloring  matter. 

Hence  the  blood  of  the  skin  gives  it  a  red  appearance,  and  the  bright- 
ness or  paleness  of  the  red,  indicates  the  health  of  the  system  in  many 
cases,  particularly  the  health  of  the  lining  of  the  stomach  and  bowels,  as 
the  same  lining  of  the  mouth  continues  on  through  the  throat,  to  line 
the  stomach,  second  stomach,  &c. 

69.  The  second  layer  of  the  lining  of  the  mouth  is  called 
the  chorion.     It  is  the  essential  part,  the  external  layer  being 
merely  a  protection.     In  the  second  layer  the  bloodvessels 
and  nerves  are  found.      Near  to  its  surface  the  bloodvessels 
form  a  network  of  superlative  delicacy  and  beauty.     Some 
parts  of  its  surface  are  formed,  as  may  be  seen  on  the  tongue, 
into  prominences  called  papillae.      In  these  some,  perhaps 
all,  the  nerves  of  the  lining  commence. 

These  nerves  must  be  threefold,  as  heretofore  seen ;  by  one  kind  a 
person  tastes ;  by  another  he  feels :  and  there  must  be  another  kind  to 
connect  this  part  with  the  nervous  system  spoken  of  in  the  general  obser- 
vations, and  called  the  organic  system,  its  nerves  being  called  organic 
nerves. 

70.  In  this  lining  there  is  found  a  multitude  of  little 


262  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

pouches  or  sacs,  called  cryptse.  They  are  like  those  of  the 
external  skin  in  their  appearance,  but  in  them  is  formed  a 
kind  of  glutinous  substance  called  mucus ;  it  can  be  seen  by 
scraping  the  tongue  with  a  spoon  or  knife.  It  is  formed  from 
the  blood. 

Its  character  of  course  will  depend  upon  the  quality  and  quantity  of 
the  blood  and  the  character  of  the  apparatus  fonning  it,  which  is  itself 
dependent  also  upon  the  quality  and  quantity  of  the  blood,  and  the  or- 
ganic nervous  system  before  mentioned.  This  system,  as  heretofore 
proved,  influences  the  circulation  of  the  blood  through  each  and  all  paits. 

Thus,  looking  in  the  mouth  to  learn  the  state  of  other  parts  of  the 
body,  is  not  useless ;  for  the  color  of  the  mouth  will  indicate  the  activity 
of  the  circulation  of  the  blood,  especially  in  the  lining  of  the  stomach, 
dtc.,  and  the  vigor  of  the  nervous  system,  at  least  in  respect  to  these 
|»arts.  The  character  of  the  mucus  will  be  another  indication  of  the 
character  of  the  blood  and  the  nervous  system,  especially  as  it  respects  the 
stomach,  second  stomach,  &c.  And  it  has  been  found  by  various  means, 
that  when  the  lining  of  the  mouth  is  "  sloughed,"  the  stomach  is  in  a  simi- 
lar condition ;  when  the  throat  has  a  certain  red  appearance,  the  second 
stomach  is  in  a  similar  state,  &c. 

71.  The  use  of  this  mucus  seems  to  be  to  preserve  the  lining  of  the 
mouth  in  a  good  condition,  and  perhaps  it  is  of  use  by  being  mingled 
with  the  food  ;  remaining  in  the  mouth,  however,  during  the  night,  it  fre- 
quently produces  a  "  bad  taste."  To  remove  it  by  rinsing  the  mouth 
with  cold  water  upon  first  rising,  is  a  good  habit.  This  habit  also  tends 
to  prevent  the  deposit  of  tartar  upon  the  teeth,  and  awaken  an  active 
circulation  of  the  blood  in  the  lining  of  the  mouth,  thus  giving  a  good 
color  to  the  gums.  If  at  the  same  time  the  throat  be  well  gargled,  it 
will  tend  to  prevent  swellings  of  the  throat  and  soreness  of  the  back 
mouth  and  throat,  and  the  "hanging  down"  of  the  palate  so  frequently 
complained  of. 

C.    Salivary  Apparatus. 

72.  This  consists  of  six  glands,  three  upon  either  side  of 
the  mouth,  and  tubes  leading  from  the  mouth  to  them. 

But  firstly,  it  will  be  best  to  describe  the  general  principle  upon  which 
all  glands  are  formed,  since  though  the  various  glands  of  the  body  differ 
in  particular  arrangement,  the  same  general  plan  is  observed  in  all. 


SEC.  1.]  THE  MOUTH.  263 

73.  Glands  are  for  the  purpose  of  presenting  a  great  extent 
of  surface  in  a  small  space.  The  simplest  form  of  a  gland  is 
that  of  a  crypta,  seen  in  Fig.  76.  A  more  compound,  but  yet 
very  simple  gland,  is  seen  in  Fig.  88  ;  while  a  compound 
gland  with  all  its  essentials  is  presented  in  Fig.  89.  By  this 
it  is  seen,  that  a  gland  is  nothing  more  than  a  tube  with  a 
great  many  branches,  about  which  there  is  an  infinite  num- 
ber of  cryptae,  and  thus  an  immense  extent  of  surface  ob- 
tained. Sometimes  the  tubes  have  no  cryptae,  but  are  very 
long  and  coiled  around  so  as  to  be  packed  in  small  com- 
pass ;  sometimes  other  ways  of  gaining  the  same  end  are 
used. 

Fig.  88. 


Fig.  88.-a,  One  of  the  simplest  glands  of  an  animal.    6,  Tube  opening  into  the  mouth. 

74.  The  next  essential  thing  is  a  great  multitude  of  blood- 
vessels  about  the  sides  of  these  tubes  in  the  glands,  and  a 
circulation  of  a  great  quantity  of  blood  from  which  the  fluid 
of  the  gland  may  be  formed.  In  the  next  place,  there  must 
be  nerves  connecting  between  the  gland  and  the  mind,  for 
when  the  salivary  glands  are  affected  with  the  mumps,  they 
ache,  and  also  when  the  mind  thinks  of  any  delicious  food, 
the  saliva  is  rapidly  formed.  There  must  also  be  a  connec- 


264  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

Fig.  89. 


Fig.  89.— Part  of  a  compound  gland,  with  tubes  and  cryptae  laid  open.  The  bteck 
lines  represent  the  larger  bloodvessels  of  the  part.  The  causes  and  appearance  of  the 
lobules  are  also  seen. 

tion  between  the  glands  and  the  organic  nervous  system,  be- 
cause  the  saliva  being  formed  from  blood  and  formed  very 
freely,  when  we  are  eating,  and  at  other  times,  in  accordance 
with  the  wants  of  the  body,  there  must  be  some  cause  for  the 
increased  circulation  of  blood  required  under  such  circum- 
stances. 

75.  'The  tube  and  cryptse  or  a  gland,  whatever  form  they  may  have, 
are  in  fact  nothing  more  than  the  lining  or  skin  of  the  part  into  which 
the  tube  opens,  slightly  and  but  slightly  changed  in  its  texture,  and  ex- 
isting in  that  form  for  the  purpose  of  presenting  much  surface  in  a  small 
space  ;  for  instance,  the  skin  lining  the  mouth  is  formed  into  a  tube 
commencing  at  the  centre  of  the  cheek,  at  a  slightly  roughish  place  easily 
felt  with  the  tongue.  It  leads  to  the  back  part  of  the  jaw,  being  readily 
felt  like  a  cord  beneath  the  skin  upon  the  outside  of  the  cheek.  At  the 
back  and  side  of  the  jaw,  just  before  the  ear,  it  forms  branches.  These 
•ubdivide,  and  about  the  twigs,  cryptse  are  formed.  Between  these  is 


SEC.  1.]  THE  MOUTH.  265 

found  a  kind  of  soft  cellular  flesh,  called  the  parenchymatous  substance 
of  the  gland.  Enclosing  the  whole  a  delicate  skin  grows,  and  the  appa- 
ratus is  formed,  and  upon  receiving  the  blood  and  nervous  influence  be- 
gins to  act. 

76.  Why,  when  the  glands  are  so  similar  in  their  structure,  the  dif- 
ferent kinds  form  such  dissimilar  fluids,  is  at  present  inexplicable.  It 
may  be  owing  to  some  difference  which  has  not  been  perceived  in  their 
structure  ;  it  may  be  owing  to  the  differences  excited  by  ?he  nervous  sys- 
tem upon  the  different  glands,  or  both  causes  may  combine  to  produce 
the  effects  seen.  It  would  seem  to  depend  much  upon  the  nervous  sys- 
tem, since  when  disease  prevents  one  part  from  fulfilling  its  duty,  it  will 
sometimes  in  a  measurably  good  degree,  be  performed  by  one  which  in 
health  performs  an  office  somewhat  similar,  perhaps,  but  yet  different. 

77.  The  small  tubes  and  cryptae  belonging  to  any  one 
branch  of  the  grand  tube  form  what  is  called  a  lobe,  and 
smaller  branches  of  the  larger  form  lobules,  &c. 

The  uneven  appearance  of  the  surface  of  many  glands,  is  owing  to 
the  lobules,  as  in  case  of  the  salivary  glands. 

78.  The  salivary   gland  just  "described,   and   its   fellow 
upon  the  other  side,  are  called  the  parotid  glands.     They  are 
about  the  size  of  a  dove's  egg,  or  a  little  larger.     Underneath 
the  under-javv,  about  two-thirds  of  the  way  from  the  centre 
of  the  chin  to  the  lower  back  corner  or  angle  of  the  jaw,  and, 
as  it  were,  between  the  jaw  and  tongue,  a  gland  about  the 
size  of  a  robin's  egg  is  found  ;  it  is  called  the  submaxillary 
(under-javv)  gland.      Tubes  from  these  open  in  the  sides  of 
the  bottom  of  the  front  part  of  the  mouth,  near  by  the  "  string  " 
which  ties  down  the  tongue. 

79.  A  short  distance  in  front  of  these,  and  rather  more 
under  the  tongue,  is  found  a  gland,  not  as  large  as  a  sparrow's 
egg,  with  several  short  tubes  opening  directly  above  and  in 
front  of  the  gland.      This,  with  its  fellow,  is  called  a  sub- 
lingual  (under-tongue)  gland. 

.80  These  different  glands  seem  to  differ  somewhat  in  their  structure 
and  in  the  influences  acting  on  them.  The  under-tongue  gland  is  seldom 
diseased,  or  its  disease  attracts  little  attention.  The  under-jaw  gland  it 

12 


266  THE  DIGESTIVE  ORGANS.  [CHAP.  1. 

liable  to  several  diseases ;  to  the  "  mumps,"  more  frequently  than  the 
sublingual,  but  less  frequently  than  the  parotid,  and  to  enlargement  and 
hardening  very  frequently.  This  seems  to  be,  sometimes  at  least,  the 
consequence  of  using  hard  water,  or  is  aggravated  thereby.  The  pro- 
gress of  disease  is  usually  so  slow,  that  attention  is  not  called  to  the  im- 
portance of  the  complaint,  till  it  is  too  late  for  the  surgeon  to  give  advice 
•with  the  best  effect.  When  this  gland  begins  to  enlarge,  it  may  be 
safely  judged  that  something  serious  is  affecting  the  system  and  that  very 
judicious  advice  should  be  taken  and  followed  for  a  long  while.  The 
most  common  disease  of  the  parotid  is  the  "  mumps,"  a  disease  some- 
times affecting  one  parotid,  sometimes  the  other,  sometimess  both ; 
sometimes  one  parotid  and  one  submaxillary  on  the  same  side,  or  on  the 
other,  or  all  the  glands  at  once,  or  several,  or  all  of  them  in  succcession. 
Sometimes  one  at  one  time,  and  another  at  another.  But  seldom  if  ever 
does  the  disease  exist  twice  in  the  same  gland.  This  is  a  matter  of  great 
surprise,  for  the  structure,  duty  and  mode  of  accomplishing  it,  are  the 
same  to  all  appearance,  before  as  after  the  disease,  and  yet  the  gland  is 
so  altered  in  regard  to  its  structure  or  the  nervous  influences  it  receives, 
that  it  cannot  be  affected  by  the  same  causes  that  produced  the  "  mumps." 
The  same  is  true  of  other  diseases,  viz.  whooping  cough,  small-pox, 
measles,  &c. ;  though  sometimes  the  system  is  not  so  changed  by  these 
diseases  that  it  cannot  be  affected  to  a  degree,  a  second,  or  even  a  third 
time,  though  always  lightly.  An  important  question  in  regard  to  these 
diseases  and  the  changes  they  produce  is,  are  they  natural,  and  do  the 
changes  they  produce  in  the  system  fit  it  to  contend  with  other  causes  of 
disease  to  better  advantage  ?  It  would  seem  from  what  evidence  can  be 
gained,  that  those  who  have  all  those  diseases,  as  they  are  called,  that 
affect  the  system  but  once,  in  their  childhood,  and  are  well  taken  care  of, 
so  that  they  entirely  recover,  are  longer  lived  and  hardier  than  others. 
All  such  diseases  seem  to  be  more  fatal  when  taken  in  advanced  life. 
The  mortality  formerly  attendant  upon  small-pox,  can  well  be  accounted 
for  by  the  treatment  pursued,  as  at  the  present  day  few  if  any  die.  In 
olden  times  a  great-grandfather  of  the  writer  being  taken  with  the  small- 
pox in  the  course  of  his  practice,  according  to  the  approved  method  of 
that  day,  without  a  reason  to  sustain  it,  immediately  shut  himself  in 
a  close  room,  kindled  a  fire  to  keep  the  apartment  very  warm,  and 
of  course  in  a  few  days  died.  People  now  ventilate  their  rooms  very 
perfectly,  eat  but  little  food,  keep  the  bowels  gently  open,  remain  quiet, 
end  if  confined  to  bed,  change  and  air  the  clothing  and  bed  itself  very 
frequently  ;  keep  themselves  cool  and  calm  as  possible,  nvoid  ail  causes 


SEC.  1.]  «x,-   THE  MOUTH.  287 

of  chills,  such  as  draughts  of  air,  &c.  ;  drink  no  stimulants,  but  as  much 
cool  (not  ice)  water  as  the  thirst  craves  ;  gargling  the  throat  with  the 
same  frequently  if  desirable.  This  course,  with  slight  variation,  and  the 
administration  of  some  medicines  as  the  physician  may  think  a  peculiar 
case  requires  being  carefully  followed,  a  person  recovers  in  a  short 
time,  not  of  small-pox  merely,  but  of  scarlet  fever,*  measles,  mumps,  &c. 
To  return  to  these  last,  many,  indeed  most  persons  when  affected  by  the 
mumps,  immediately  cover  the  face  with  a  handkerchief,  <fcc.,  and  con- 
fine themselves  to  the  room  or  house.  But  the  opposite  course  is  advisa- 
ble, to  which  the  writer  can  testify  from  recent  experience.  Nothing 
should  be  used  to  cover  the  face,  but  the  face  over  the  region  of  the  dis- 
ease should  be  sponged  with  cold  water  ;  avoid  taking  cold,  eat  lightly, 
keep  the  bowels  open,  breathe  pure  air,  and  take  light  exercise. 

D.   The  Muscles  of  the  Mouth. 

81.  These  may  be  considered  as  forming  three  classes. 
1st.  Those  which  raise  and  depress  the  jaw,  and  move  it 
from  side  to  side.     Those  which  raise  the  jaw  are  four  in 
number  upon  each  side.     The  temporal  muscle  will  be  felt 
by  placing  the  finger  upon  the  temple  while  chewing,  and  if 
the   thumb   be   placed    upon  the  jaw  below,  the  masseter 
muscle  will  be  felt  (Lith.  PI.  1,  Fig.  1).      Within  the  jaw, 
and  passing  from  it  to  certain  projections  or  processes  at  the 
bottom  of  the  skull,  two  other  muscles,  called  the  internal 
and  external  pterygoid,  are  found  (Fig.  90).      They  assist 
in  raising  the  jaw,  and  when  those  upon  either  side  act,  they 
move  the  jaw  inward  upon   that  side  ;    then   the   opposite 
muscles  contracting  will  produce  a  grinding  motion  of  the 
jaws.     They  can  also  shoot  the  jaw  forward. 

The  muscles  that  draw  the  jaw  down  are  numerous,  and 
are  not  worthy  of  mention,  except  the  digastric,  described 
in  a  previous  paragraph. 

82.  2d.  The   muscles  of  the   tongue.     Some  of  them 

*  Some  do  not  think  this  contagious,  or  at  all  belonging  to  the  cata- 
logue of  small-pox,  measles,  &c.  In  some  respects  it  doee,  in  others 


258  THE  DIGESTIVE  ORGANS.  [CBAP.  I. 

Fig.  90. 


Fig.  90. — The  two  pterygpid  muscles.  The  zyeomatic  arch  and  the  greater  part 
of  the  ramus  of  the  lower  jaw  have  been  removed  in  order  to  bring  these  muscle* 
into  view.  1,  The  sphenoid  origin  of  the  external  pterygoid  muscle.  2,  Its  pterygoid 
origin.  3,  The  internal  pterygoid  muscle. 

reach  from  the  centre  of  the  chin  directly  back  into  the 
body  of  the  tongue,  others  turn  upward  to  the  tip,  as  seen 
in  Fig.  91.  Some  reach  forward  from  the  bone  at  the  base 
of  the  tongue  to  the  tip,  the  tongue  being  composed  almost 
entirely  of  muscular  fibres ;  by  the  contraction  of  some  or 
many  of  which,  the  varied  movements  of  the  tongue  are 
produced.  The  use  of  these  movements  in  eating,  is  to  roll 
the  food  under  the  teeth ;  to  gather  it  into  a  ball  when  it  is  to 
be  swallowed,  and  pass  it  back  to  the  throat. 

83.  3d.  The  muscles  of  the  cheeks  (Lith.  PI.  1,  Fig.  1). 
They  are  of  use  in  bringing  the  food  under  the  teeth,  and  also 
assist  in  taking  the  food  and  drink  into  the  mouth,  especially 
when  taken  by  sucking ;  they  also  close  the  mouth.  They 
are  also  muscles  of  expression,  as  it  is  termed,  and  are  so 
numerous  that  it  is  easily  seen  how,  by  a  slight  peculiarity 
of  the  different  muscles,  different  expressions  will  be  given 
to  the  features. 

84.  All  the  muscles  of  these  classes  depend  upon  the  blood  for  their 
vigor,  and  as  the  circulation  of  it  is  under  the  control  of  the  nervous 
system  of  organic  life,  the  muscles  must  be  connected  with  it ;  as  they 
must  also  be,  that  the  changes  taking  place  in  them  may  go  on  regu- 


SEC.  l.J 


269 


Fig.  91.— The  styloid  muscles  and  the  muscles  of  the  tongue.  1,  A  portion  of  the 
temporal  bone  of  the  left  side  of  the  skull,  including  the  styloiil  and  mastoid  processes, 
and  the  meatus  auditorius  externus.  2,  2,  The  right  side  of  the  lower  jaw,  divided  at 
its  symphysis;  the  left  side  having  been  removed.  3,  The  tongue.  4,  The  genio- 
hyoideus  muscle.  5,  The  genio-hyo-glossus.  6,  The  hyo-glossus  muscle ;  its  basio- 
glossus  portion.  7,  Its  cerato-glossus  portion.  8,  The  anterior  fibres  of  the  lingualis 
issuing  from  between  the  hyo  glossus  and  genio-hyo-glossus.  9,  The  stylo-glossus 
muscle,  with  a  small  portion  of  the  stylo-maxillary  ligament.  10,  The  stylo-hyoid. 
11,  The  stylo-pharyngus  muscle.  12.  The  os-hyoides.  "13,  The  thyro-hyoidean  mem- 
brane. 14,  The  thyroid  cartilage.  15,  The  thyro-hyoideus  muscle  arising  from  the 
oblique  line  on  the  thyroid  cartilage.  16,  The  cricoicl  cartilaffe.  17,  The  crico-thyroi- 
dean  membrane,  through  which  the  operation  of  laryngotomy  is  performed.  18,  The 
trachea.  J9,  The  commencement  of  the  oesophagus. 

larly.  All  these  must  also  be  connected  with  the  mind,  as  they  obey 
the  mandates  of  the  mind  when  it  desires  them  to  contract,  and  their 
states  sometimes  produce  pain.  The  muscles  of  the  face  seem  to  be 
peculiarly  connected  with  that  part  of  the  brain  or  nervous  system  acted 
upon  by  the  emotions :  for  all  the  passions  and  emotions  of  the  mind 
are  usually  expressed  with  more  accuracy  by  them  than  they  could  be 
by  any  language.  The  permanent  feelings  of  the  mind  always  stamp 
themselves  upon  these  causes  of  the  features.  Knowing  this,  a  person 
should  beware  of  trusting  to  his  power  of  putting  on  a  Sunday  face  ;  his 
muscles  of  expression  will  betray  him.  These  muscles,  from  disease  of 
the  nervous  system,  are  sometimes  paralyzed,  or  one  class,  or  part  of  a 
class  only,  or  by  a  different  disease  of  some  part  of  the  nervous  system, 


270  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

they  are  thrown  into  action,  which  the  mind  neither  produces  nor  con- 
trols. The  tongue  will  be  thrown  out,  and  frightfully  bitten  by  the 
muscles  suddenly  closing  the  jaws ;  at  the  same  time,  the  muscles  of  the 
face  producing  hideous  contortions  of  the  features.  Sometimes  the 
nervous  influence,  instead  of  acting  at  intervals,  is  by  disease  caused  to 
act  continuously,  closing  the  jaws  firmly  and  producing  lock-jaw,  or 
perhaps  acts  on  all  the  classes  of  muscles  with  similar  effects. 

85.  The  muscles  of  the  face,  of  the  tongue,  and  of  the 
jaw,  are  also  divided  into  those  of  the  right  and  those  of  the 
left  side,  which  receive  their  nerves  from  the  two  sides  of 
the  nervous  system. 

Thus  the  muscles  of  one  side  may  be  paralyzed,  and  those  of  the 
other  side  sound,  drawing  the  face  or  the  tongue  to  that  side,  the  jaw 
upon  the  diseased  side  dropping  down.  Other  diseases  of  the  nervous 
system  may  exhibit  themselves,  of  course,  in  a  similar  manner  in  the 
muscles  of  either  side,  according  as  the  nervous  system  of  either  side  ia 
affected. 

86.  Back  mouth.      At  the  sides  of  the  commencement  of 
this,  are  found  what   are   called   the   amygdaloid   (almond- 
shaped)  glands.     Their  particular  use  is  not  known. 

They  are  frequently  swollen  as  one  of  the  effects  of  colds,  and  fre- 
quently become  enlarged,  producing  a  difficulty  in  breathing,  swallowing, 
and  speaking,  which  is  often  overcome  by  gargling  the  throat  with  cold 
water. 

87.  Above  the  base  of  the  tongue,  the  soft  palate  is  found 
hanging  in  the  back  part  of  the  mouth,  arched  upon  either 
side  of  a  central   point,   commonly  called  the  palate,  but 
properly  the  uvula.      The  soft  palate  is  formed  mostly  of 
muscles,  covered  by  the  lining  of  the  mouth,  which  passes 
round  the  edge  of  the  palate  and  covers  the  other  side  of  it, 
which  becomes  the  floor  of  the  nose. 

88.  The  central  point  of  the  palate,  the  uvula,  often  becomes  too  long, 
and  hanging  down,  it  produces  almost  constant  tickling  and  inclination 
to  cough.  The  application  of  gargles  of  cold  water,  or  more  astringent 
substances,  usually  are  sufficient  for  this  evil ;  if  not,  a  portion  of  tha 
part  must  be  clipped  off. 


SEC.  1.]  THE  MOUTH.  271 

89.  The  action  of  some  of  the  muscles  of  the  palate  can 
raise  it  to  a  horizontal  position,  when  it  will  reach  to  the 
back  part  of  the  throat,  and  cut  off  all  communication  with 
the  nose.  The  action  of  the  other  muscles  will  draw  the  soft 
palate  close  upon  the  tongue,  and  close  the  passage  from  the 
throat  to  the  front  mouth. 

90.  Below,  the  throat  or  back  mouth  terminates  in  the 
oesophagus  and  the  windpipe,  which  is  placed  beneath  the 
back  of  the  tongue.     The  opening  into  it  is  at  its  upper  and 
back  part.     Over  this  opening  a  thin  piece  of  flexible  car- 
tilage is  placed,  attached  to  the  under  part  of  the  tongue 
and  upper  front  edge  of  the  windpipe.     This  valve,  as  it  is 
sometimes  called,  can  be  easily  felt  by  the  finger  passed 
along  over  the  back  surface  of  the  tongue.      Against  this 
the  windpipe  is  raised  up  when  food  is  swallowed  into  the 
throat,  sliding  over  the  opening,  into  the  meat-pipe,  gullet, 
swallow  or  oesophagus. 

91.  This  is  a  tube  represented  by  Fig.  25,  from  nine  to 
eighteen  inches  in  length,  composed  of  muscular  fibres,  lined 
with  a  continuation  of  the  lining  of  the  mouth.     Food  which 
is  swallowed  into  this  tube,  tunnel-shaped  above,  is  imme- 
diately pressed  upon  by  the  upper  muscles  of  the  upper  part 
of  the   oesophagus,   and   thus  forced   down   a   little,   when 
another   portion   of   the  muscular  fibres   contracting,   it   is 
forced  down  still  further,  till  by  the  successive  contraction 
of  the  different  parts  of  the  swallow,  the  food  is  deposited  in 
the  stomach. 

92.  When  the  tube  is  empty,  the  sides  are  in  contact 
with  each  other;  it  can  be  distended  from  half  an  inch  to 
two  inches  in  different  persons.     When  substance  is  thrown 
up  from  the  stomach,  a  contracting  action  of  the  oesophagus 
takes  place  from  below  upwards. 

Sometimes  as  the  food  is  swallowed,  the  fibres  above  the  food  con- 
tract, while  those  below  either  convulsively  contract,  or  refuse  to  relax  or 


272  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

open.  This  produces  acute  distress,  but  usually  only  for  a  moment. 
Similar  pain  is  felt  sometimes  from  swallowing  a  laiger  mouthful  of  food 
than  a  person  ought.  Other  causes  sometimes  detain  the  food  in  the 
throat.  If  the  substance  be  of  a  harmless  character,  it  may  be  forced 
down  into  the  stomach  by  a  smooth  piece  of  ratan,  whalebone,  or  plia- 
ble "sprout"  of  a  tree.  Whatever  is  used  should  be  quite  flexible,  yet 
pretty  strong,  and  about  as  large  as  a  pencil-case — a  little  la.ger  or 
smaller,  as  is  convenient.  One  end  should  be  covered  with  a  piece  of 
fine  sponge  strongly  tied  on  with  thread,  or  a  bit  of  cloth  will  be  better 
than  nothing ;  if  nothing  else  be  at  hand,  a  green  shoot  of  a  tree  can  be 
bruised  with  a  stone  so  as  to  be  somewhat  soft,  or  it  can  be  made  very 
smooth  and  thus  used.  The  gullet  is  directly  in  front  of  the  back-bone, 
so  that  if  the  head  be  put  back  as  far  as  possible,  the  opening  of  the 
mouth  is  nearly  in  a  line  with  the  meat-pipe,  and  any  thing  can  easily 
be  passed,  even  by  a  child,  through  the  mouth  and  throat  into  the  sto- 
mach, and  by  a  stick  or  the  like,  food  could  be  forced  on.  If  any  thing 
like  a  fish-hook,  pins,  needles,  &c  ,  be  lodged  in  the  meat-pipe,  a  large 
piece  of  sponge  tied  around  the  end  of  a  stick  can  sometimes  be  forced 
down  the  gullet,  carrying  with  it  the  harmful  object,  which  will  not  prove 
as  obnoxious  in  the  stomach  ;  or  if  the  sponge  can  be  crowded  past  the 
object,  in  being  raised  it  may  remove  the  object  also.  The  surgeon 
should  be  called  in  such  a  case  as  soon  as  possible,  as  his  ingenuity  and 
experience  may  expedite  matters  more  skilfully  than  others.  Sometimes 
the  physician  will  think  it  advisable  to  give  an  emetic  by  injecting  it  into 
the  veins,  when  it  will  soon  cause  the  stomach  to  throw  off  its  contents, 
which  may  bring  up  with  them  the  cause  of  trouble. 

93.  There  is  one  thing  in  respect  to  the  muscles  of  the  oesophagus 
worthy  of  notice.  They  are  not  under  the  control  of  the  mind.  A  per- 
son can  swallow  any  thing  into  the  throat,  but  once  there,  he  has  no 
further  control ;  neither  can  he  produce  the  movements  of  swallowing, 
except  by  passing  something  into  the  throat.  The  muscles  of  the  meat- 
pipe  must  of  course  receive  nervous  influence  from  some  source.  It  is 
not  the  action  of  the  food  when  touching  the  muscles  which  causes  them 
to  contract,  for  it  is  those  just  above  the  food,  which  by  contracting,  press 
the  food  along  ;  therefore  it  must  be,  that  when  the  food  touches  one:  por- 
tion of  the  meat-pipe,  an  effect  is  produced  upon  the  nervous  system  of 
organic  life,  and  then  an  influence  is  exerted  upon  the  muscular  fibres 
just  above  where  the  food  touches  the  oesophagus.  Here  is  seen  another 
duty  of  the  organic  nervous  system,  viz.,  to  cause  certain  muscles  to  con- 
tract ;  and  likewise  another  illustration  of  the  fact,  that  the  mind  is  re- 


SEC.  2.]  THE   STOMACH.  273 

lieved  of  all  duties  that  can  be  well  performed  without  its  supervision. 
» There  is,  however,  a  connection  between  the  mind  and  these  muscles, 
as  is  evident  from  the  pain  they  produce. 

94.  Toward  the  lower  extremity,  the  oesophagus  comes 
forward,  and  a  little  to  the  left  of  the  back-bone,  terminating 
in  the  stomach  nearly  on  a  level  with  the  lower  point  of  the 
breasi-bone,  and  a  little  to  the  left  of  the  centre  of  the  body. 


SECTION  2. — The  Stomach. 


95.  The  food,  when  swallowed  from  the  mouth,  is  not  different  from 
what  it  was  when  received  info  the  mouth,  except  that  it  is,  or  should 
be,  ground  finely  and  mingled  with  saliva.      It  is  in  the  same  condition 
when  it  reaches  the  stomach  as  when  it  leaves  the  mouth.      In  the  sto- 
mach it  is  to  undergo  what  may  properly  be  called  a  change — a  change 
which  requires  considerable  time — and  also  that  the  food  be  mingled  with 
certain  fluids  formed  in  the  stomach  for  their  peculiar  purposes.      The 
stomach  must  therefore  be  a  pouch  of  considerable  size — the  size  varying 
as  the  case  may  require,  for  sometimes  much  food  and  sometimes  but 
little  is  required.     The  stomach  must  be  so  constructed  that  it  can  mingle 
its  juices  with  the  food,  and  must  receive  a  large  supply  of  blood,  from 
which  its  juices  are  formed,  and  the  supply  of  blood  must  vary  as  the 
system  requires  the  preparation  of  much  or  little  food.      Nervous  influ- 
ence must  also  be  exerted  upon  the  stomach,  that  the  fulfilment  of  all  its 
duties  may  be  regulated.     The  stomach  must  also  be  connected  with  the 
mind.     All  these  things  are  found  to  exist  as  it  would  be  supposed  they 
should. 

96.  As  the  stomach  is  hidden  from  our  view  under  ordinary  circum- 
stances, it  -might  be  thought  by  some,  that  statements  in  respect  to  the 
operations  of  this  organ  must  be  entirely  conjectural ;  and  so  they  were 
till  within  a  few  years.     In  the  year  1822,  however,  a  young  man,  Alexis 
St.  Martin  by  name,  a  Canadian  by  birth,  but  at  the  time  in  Michigan 
in  the  United  States  service,  was  accidentally  wounded  by  the  discharge 
of  a  gun  ;  the  muzzle  of  which  was  about  a  yard  behind  and  a  little  to 
the  left  of  him,  and  pointed  across  his  side,  which  was  torn  open  by  the 
buckshot  and  somewhat  burnt  by  the  powder  with  which  the  gun  wat 

12* 


274  THE  DIGESTIVE  ORGANS.  [CHAP.  1. 

loaded.  Dr.  Beaumont,  U.  S.  surgeon,  was  immediately  called.  He 
found,  as  he  says,  a  portion  as  large  as  a  turkey's  egg,  of  the  left  lung,< 
pushed  out  through  the  opening  made  ;  and  noticed,  also,  that  the  food 
eaten  for  breakfast  by  St.  Martin  about  an  hour  before,  was  passing  out 
in  a  half-digested  state.  Of  course,  the  stomach  was  injured.  Strange 
to  say,  in  about  ten  months  after  this  St.  Martin  was  well,  to  the  great 
credit  of  Dr.  B.  Still  more  strange,  and  fortunate  for  the  world  and  ap- 
parently without  injury  to  St.  Martin,  though  the  opening  in  the  side 
closed  up  so  as  to  cover  in  (he  lung,  the  edges  of  the  wound  in  the  stomach 
refused  to  "  grow  together,"  but  grew  to  the  edges  of  the  external  wound 
in  the  side — thus  leaving  an  opening,  about  two  and  a  half  inches  in  cir- 
cumference, through  the  side  into  the  stomach.  Through  this  opening 
any  thing  could  be  passed  into,  or  taken  from  the  stomach ;  or  the 
stomach  could  be  examined  under  any  different  circumstances.  In  about 
ten  months  from  the  recovery  of  St  Martin,a  kind  of  valve  or  apron  began 
to  grow  down  from  the  upper  edge  of  the  opening  of  the  stomach.  It 
hung,  so  to  speak,  within  the  opening  like  a  curtain,  retaining  the  food  ; 
but  it  could  be  pressed  in,  and  the  stomach  examined  as  before.  Dr.  B. 
hastened  to  improve  the  opportunity  ;  and  with  much  apparent  accuracy 
and  particularity,  made  notes  of  his  observations  and  experiments.  With 
his  notes  in  hand,  and  the  results  of  so  many  experiments  as  have  been 
tried  on  man  and  animals,  we  may  advance  to  the  subjects  under  consi- 
deration with  considerable  assurance  of  being  compensated  with  positive 
knowledge. 

97.  The  stomach  is  situated  in  that  part  of  the  trunk, 
called  the  abdomen — the  large  cavity  found  below  the  dia- 
phragm (Lith.  PL  3,  Fig.  1).  The  diaphragm  is  a  muscu- 
lar and  tendinous  partition,  arching  upward  very  much.  It 
is  connected  by  its  outer  edge  to  the  ribs  and  cartilages  at  the 
bottom  of  the  chest,  to  the  lower  part  of  the  breast-bone  and 
to  the  back-bone.  It  forms  the  roof  of  the  abdomen,  which 
from  the  arched  form  of  the  diaphragm,  reaches  up  under 
the  ribs  more  or  less  according  to  the  arch  of  the  diaphragm; 
and  that  varies  very  much  on  two  accounts,  as  in  Figs.  92  and 
93.  For  as  the  ribs  are  raised  up  when  the  breath  is  drawn 
in,  as  every  one  can  perceive  is  the  case  by  placing  the 
hards  upon  the  sides  and  inhaling  a  full  breath,  the  arch  of 


SEC.  2.] 


THE  STOMACH. 


275 


the  diaphragm  will  be  less  unless  it  passes  up  at  the  same 
time,  instead  of  which  it  is  brought  down  by  the  contraction 
of  the  muscular  part  of  the  diaphragm. 

Fig.  92. 


Fig.  92.— The  back-bone  is  easily  recognized.  The  pillars  of  the  diaphragm  are 
connected  with  it  at  1,  wnich  is  not  a  movable  point,  a8  is  1  at  the  opposite  and  front 
eide  of  the  cheat,  which,  when  it  is  raised  up,  carries  the  point  1,  outward  and  upward 
to  2.  The  continuous  line  1,  1,  is  the  diaphragm  when  the  breath  is  thrown  out ;  and 
close  underneath  it,  the  liver  and  stomach  are  situated,  as  in  Fig.  96.  The  dotted  liae 
1, 2  is  the  position  of  the  diaphragm  when  contracted  at  the  same  time  the  chest  is 
raised,  and  of  course  the  organs  of  the  abdomen  are  pressed  down  and  outward  by  all 
the  space  between  the  line  1,1,  and  the  dotted  line  1, 2.  The  dotted  line  beneath  2  is 
the  wall  of  the  abdomen,  when  the  diaphragm  is  contracted.  The  line  beneath  1  is  th« 
wall  of  the  abdomen,  when  contracted. 


98.  The  sides  of  the  abdomen  are  essentially  composed 
of  several  layers  of  muscles,  (Lith.  PL  1,  Fig.  1,)  covered 
by  the  skin  without  and  lined  by  a  skin  or  membrane,  called 
the  peritoneal  coat.  When  the  stomach,  second  stomach,  and 
other  organs  of  the  abdomen  are  full,  the  muscles  are  dis^ 


276 


THE  DIGESTIVE  ORGANS, 
Fig.  93. 


[CHAP.  i. 


Fig.  93. — Back  view  of  a  perpendicular  section  of  the  lower  part  ci"  ihe  Jiest  and 
upper  part  of  the  abdomen,  through  the  centre  of  the  body.  The  con'.inuous  lines 
show  the  outline  of  the  body  and  diaphragm  when  the  sides  of  the  abdomen  are  con- 
tracted, and  the  diaphragm  and  the  levator  muscles  of  the  chest  relaxed.  The  stomach, 
liver,  &c.,  are  closely  drawn  up  underneath  the  diaphragm,  as  in  Fig.  97.  The  dotted 
lines  exhibit  the  outline  of  the  body  and  diaphragm  when  the  chest'is  raised  up,  and 
of  course  the  points  1,  1,  carried  outward  to  2,  2,  and  the  organs  of  the  abdomen  are 
pressed  downward  and  outward,  distending  the  sides  of  the  abdomen,  as  seen  below  2, 
2,  or  felt  by  the  hands  placed  on  the  sides  of  the  abdomen  when  the  breath  is  drawn 
in.  At  3,  it  is  observed  that  the  dotted  lines  are  but  a  little  below  the  position  of  the 
continuous  lines.  That  point  of  the  diaphragm  is  nearly  stationary,  above  it  the 
heart  is  found ;  and  the  partitions  upon  either  side  of  the  heart,  dividing  the  chest  into 
three  apartments,  are  attached  to  the  diaphragm,  and  with  other  causes  prevent  exten- 
sive movement  of  that  point,  which  is  toot  only  unnecessary  but  would  be  injurious. 
Upon  either  side  of  3,  the  arches  of  the  diaphragm  are  seen ;  upon  the  right,  the  arch 
is  naturally  the  greater,  owing  to  the  position  of  the  liver  beneath  it ;  which  causes 
also  the  arch  3, 2,  to  be  more  distinct  than  represented  by  the  dotted  lines. 


tended ;  when  these  organs  are  empty  the  muscles  contract 
so  as  to  produce  a  constant,  greater  or  less,  pressure  on  the 
organs  within  the  abdomen.  The  abdomen  is  always  full : 
therefore,  if  there  be  but  little  in  it,  the  abdomen  is  small  in 
external  circumference ;  if  the  abdomen  contain  much,  the 
external  circumference  is  correspondingly  large. 

99.  When,  therefore,  the  arch  of  the  diaphragm  is  drawn  down  in 
breathing,  the  organs  of  the  abdomen  must  be  pressed  down,  and  also 
compressed  if  the  muscles  of  the  side  of  the  abdomen  do  not  yield  or  re- 
lax ;  and  by  placing  the  hand  upon  the  abdomen  when  the  breath  is 
drawn  in,  it  will  be  perceived  to  distend,  thus  giving  room  for  the  organ* 


SEC.  2.]  THE  STOMACH.  277 

pressed  down  by  the  diaphragm.  Again,  it  will  be  seen  by  Lith.  PI.  1, 
Fig.  1,  that  some  of  the  muscles  of  the  front  part  of  the  abdomen  stretch 
from  the  ribs  to  the  front  part  of  the  pelvis.  Except,  therefore,  these 
muscles  relax,  the  ribs  cannot  be  raised  up  as  they  are  when  the  breath 
is  drawn  in. 

100.  The  muscles  forming  the  walls  of  the  abdomen  re- 
lax, therefore,  to  allow  the  diaphragm  to  press  the  organs  of 
the  abdomen  down,  and  to  allow  the  ribs  to  be  raised. 

101.  The  contraction  of  the  muscles  of  the  sides  of  the 
abdomen  will  have  just  the  contrary  effect,  viz.,  it  will  draw 
down  the  ribs  and  press  upon  the  organs  within  the  abdomen, 
and  cause  them  to  press  upon  the  diaphragm,  and  press  it  up 
if  it  be  relaxed ;  if  it  be  contracted,  the  organs  of  the  ab- 
domen will  be  pressed  upon,  and  if  with  sufficient  force  their 
contents   will    be   discharged — as   when    in    vomiting,   the 
stomach  is  so  forcibly  pressed  as  to  overcome  the  lower  rings 
of  the  oesophagus,  which  by  contracting,  retain  its  contents. 

102.  The  force  with  which  the  muscles  of  the  abdomen 
will  press  upon  its  organs,  will  depend  in  the  first  place,  upon 
the  contents  of  the  organs. 

If  the  organs  be  full,  as  is  noticed  after  a  hearty  dinner,  the  pressure 
will  be  considerable  ;  and  breathing  is  performed  with  difficulty,  because 
the  diaphragm  finds  a  difficulty  in  pressing  down  the  organs  of  the  abdo- 
men, when,  by  their  fulness,  they  have  already  distended  the  sides  of 
the  abdomen  almost  to  their  limit.  While,  if  little  has  been  eaten,  the 
movements  of  the  diaphragm  may  be  extensive  and  performed  with  ease ; 
hence  why  a  person  speaks  or  sings  with  ease,  "  on  an  empty  stomach." 

103.  The  pressure  upon  the  abdominal  organs  depends, 
in  the  second  place,  upon  the  position  in  which  a  person 
stands,  or  sits. 

If  the  body  be  erect,  the  muscles  of  the  sides  of  the  abdomen  are 
made  tense,  or  the  opposite  of  relaxed,  and  the  sides  of  the  abdomen 
cannot  of  course  be  easily  distended ;  more  force  is  exerted  upon  the  ab- 
dominal organs,  and  the  diaphragm  is  drawn  down  with  greater  diffi- 
culty, and  the  ribs  also  raised  with  greater  difficulty  ;  that  is,  the  breath 
is  drawn  in  with  greater  difficulty.  If  the  body  be  somewhat  bent,  how- 


278  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

ever,  the  muscles  are  correspondingly  relaxed  and  the  breath  drawn  in 
with  ease — as  the  organs  of  the  abdomen  are  compressed  but  little. 
Hence  when  a  person  has  eaten  a  hearty  dinner,  he  sits  in  a  curved  pos- 
ture, and  when  the  stomach,  bowels,  or  other  organs  of  the  abdomen  are 
sore  upon  pressure,  he  places  a  pillow  under  his  shoulders  and  draws  up 
the  knees — as  then  the  muscles  are  relaxed  ;  and  when  he  wishes  to 
draw  in  a  full  breath,  he  also  curves  his  body  forward  a  little. 

If  on  the  other  hand,  the  body  be  very  much  curved,  the  muscles  of 
the  sides  of  the  abdomen  must  contract  very  much  before  they  will  begin 
to  press  upon  the  contents  of  the  abdomen,  and  thus  cause  the  breath  to 
be  thrown  out,  while  if  the  body  be  erect,  a  very  slight  contraction  of 
the  muscles  will  exert  great  force.  Hence  the  position  which  is  best  for 
drawing  in  the  breath  is  not  the  best  for  throwing  the  breath  out.  Thus 
powerful  singers  will  be  observed  to  take  advantage  of  each  position  of 
the  body,  curving  forward  a  little  when  the  breath  is  drawn  in  and 
straightening  themselves  up,  and  indeed  curving  slightly  backward 
sometimes,  to  give  the  muscles  great  power  in  throwing  out  the  voice.  It 
•would  seem  therefore,  that  no  one  position  is  always  right,  but  that  any 
position  is  sometimes  right.  An  intermediate  posture  between  very 
straight  and  curved,  being  the  general  direction  best  to  follow,  especially 
during  sleep  ;  but  a  frequent  change  of  posture  is  evidently  the  intention 
of  nature,  and  all  supports  and  articles  of  dress  which  prevent  the  rising 
of  the  ribs  or  distention  of  the  muscles  of  the  abdomen,  are  evidently  in- 
jurious. 

104.  The  pressure  exerted  upon  the  organs  of  the  ab- 
domen will  depend,  in  the  third  place,  upon  the  health  of  the 
muscles. 

This  varies  much  in  different  persons,  and  can  be  improved  by  » 
judicious  course  of  training.  This  is  accomplished  by  a  course  o"  read- 
ing, singing,  speaking,  blowing  upon  wind  instruments,  or  any  exercise 
calling  into  action  the  breathing  muscles,  gentle  at  first,  but  made  more 
severe  as  they  gain  strength. 

105.  The  pressure  of  the  muscles  upon  the  organs  of  the 
abdomen  depends,  in  the  fourth  place,  upon  the  exercise  of  the 
system. 

Almost  any  exercise  increases  the  action  of  the  breathing  muscles, 
and  some  kinds,  such  as  lifting,  &c.,  produce  immense  pressure  upon  the 
contents  of  the  abdomen. 


SEC.  2.]  TITE  STOMACH.  279 

106.  On  every  account  it  will  be  found  that  the  stomach  has  a  most 
favorable  location.     In  the  upper  part  of  the  body  a  framework  was 
necessary  to  support  the  arms,  and  within  this  the  lungs  and  heart  might 
be  most  advantageously  placed,  while  the  stomach  required  a  position 
where  it  could  increase  or  diminish  in  size,  as  the  necessity  of  the  case 
required,  viz.,  as  the  system  should  require  much  or  little  food.     Gentle 
pressure  while  the  stomach  is  digesting  food  is  also  highly  advantageous 
to  its  action.     The  abdomen  is  therefore  precisely  adapted  to  the  wants 
of  the  stomach,  while  every  action  of  it  is  equally  advantageous  to  the 
heart  and  lungs,  as  hereafter  shown. 

107.  The  stomach  is  a  muscular  pouch  or  bag,  covered 
with  a  membrane  called  the  peritoneal  coat,  and  lined  with 
what  has  the  several  names  of  mucous  coat,  villous  coat, 
lining  membrane,  &c. 

108.  The  muscular  coat  is  itself  composed  of  several  dif- 
ferent layers,  the   fibres   in   one   layer  passing  around  the 
stomach,  as  in  Fig.  26 ;  the  fibres  in  another  layer  passing 
from  one  extremity  towards  the  other.     In  another  layer  the 
fibres  pass  across  the  fibres  of  the  other  two.     In  the  human 
stomach  the  layers  are  not  very  readily  separated,  for  the 
fibres  of  the  layers  are  interwoven  with  each  other  very  in- 
timately, and  the  whole  thickness  of  the  stomach  is  not  very 
great,  and  the  muscles  of  it  are,  therefore,  correspondingly 
delicate.     In  a  piece  of  tripe,  (the  stomach  of  a  beef,)  which 
is  thick,  the  layers  are  very  readily  seen.     By  the  contrac- 
tion of  the  circular  fibres  of  the  large  extremity,  the  food  will 
be  passed  into  the  small  extremity,  the  fibres  of  which  must 
relax,  and  vice  versa,  the  contraction  of  the  circular  fibres 
of  the  small  extremity  of  the  stomach  will  press  the  food  back 
again.    The  contraction  of  the  longitudinal  fibres  of  the  stom- 
ach will  draw  the   extremities  of  the  stomach  towards  each 
other,  while  the  contraction  of  all  the  muscles  of  the  stomach 
will  lessen  its  size  in  every  direction.     The  covering  of  the 
stomach  will  be  spoken  of  hereafter. 

109.  The  lining  of  the  stomach  is  a  continuation  of  the 


280  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

lining  of  the  mouth  and  oesophagus.  It  is,  however,  somewhat 
altered  in  appearance,  and  has  some  new  duties  to  perform. 
Like  the  lining  of  the  mouth  and  throat,  it  contains  many 
cryptse,  from  the  mouths  of  which,  a  slimy  substance,  like 
that  of  the  mouth,  flows  out  upon  the  lining  of  the  stomach. 

Whether  in  a  healthy  state  of  the  stomach  the  quality  of  this  sub- 
stance varies  at  different  times,  that  is,  whether  more  is  formed  when 
food  is  taken  than  when  the  stomach  is  empty,  is  not  known.  It  is 
formed  from  the  blood,  and  of  course  its  quality  and  quantity  will  depend 
upon  the  quality  and  quantity  of  blood  from  which  it  is  formed,  the 
healthy  state  of  the  apparatus  in  which  it  is  formed,  and  the  state  or  pow- 
er of  the  nervous  system  which  causes  it  to  be  formed. 

110.  The  whole  inner  surface  of  the  stomach  is  formed 
into  innumerable  points,  like  the  "  nap  "  of  very  delicate  vel- 
vet. They  are  called  villi,  and  give  the  stomach  a  kind  of 
fleecy,  velvety,  cloudy,  and  very  delicate  appearance  (Fig. 
94).  Their  specific  use  is  not  known. 

Fig.  94. 


Fig.  9J\— Portion  of  the  lining  of  the  stomach. 

111.  The  chief  office  of  the  lining  of  the  stomach,  is  to 
form,  from  the  blood,  a  fluid  called  the  gastric  (stomach) 
juice.  Its  appearance  to  the  eye  is  that  of  spring  water. 
It  has  no  very  peculiar  smell  or  taste,  varying  in  these  re- 
spects in  different  cases.  But  it  has  a  very  powerful  and 
peculiar  effect  upon  food  submitted  to  its  action.  In  a  short 


SEC.  2.]  THE  STOMACH.  »          281 

time  the  food  will  undergo  a  change,  very  apparent  to  the 
eye,  smell,  or  taste. 

In  what,  however,  its  properties  consist,  or  how  it  produces  its  effects, 
or  what  precise  changes  take  place  in  the  food  by  its  action,  has  never 
yet  with  certainty  been  learned.  It  is  curious,  for  instance,  that  the 
slightest  difference,  either  in  smell,  taste,  or  looks,  cannot  be  detected 
between  the  gastric  juice  of  a  dog  and  that  of  a  sheep ;  and  yet  grass 
will  remain  unaffected  in  the  gastric  juice  of  the  dog,  and  meat,  in  like 
manner,  will  not  be  acted  on  in  the  gastric  juice  of  a  sheep. 

112.  In  what  particular  part  of  the  lining  of  the  stomach 
the  gastric  juice  is  formed,  is  not  determined.  It  appears  in  the 
stomach  very  much  as  perspiration  appears  on  the  side  of  the 
forehead,  viz.,  it  is  seen  starting  out  over  the  inner  surface  of 
the  stomach,  in  very  minute   drops,  which  are  sometimes 
poured  out  so  freely  that  they  gather  into  larger  drops,  or 
even  trickle  down  the  sides  of  the  stomach  as  the  perspira- 
tion sometimes  streams  down  the  face. 

113.  The  quantity  and  quality  of  the  gastric  juice  will 
depend  upon  the  quantity  and  quality  of  blood  from  which 
it  is  formed  ;  the  condition  of  the  apparatus  in  which  it  is 
formed,  and  the  health  of  the  nervous  system,  by  the  influ- 
ence of  which  it  is  formed. 

114.  When  the  system  was  healthy,  gastric  juice  was 
found  by  Dr.  B.  not  to  be  continually  formed,  as  the  saliva 
is,  but  only  when  food  was  required  and  swallowed.     If  food 
were  taken  when  it  was  not  needed  by  the  system,  the  gas- 
tric juice  would  not  appear,  and  of  course  the  food  could 
not  be  acted  upon.     But  it  would  act  on  the  stomach  very 
injuriously,  producing  inflammation.     To  eat  food  when  it  is 
not  needed,  is  therefore  exceedingly  injurious. 

115.  If  the  system  needed  food,  and  unwholesome  sub. 
stances  were  swallowed,  the  gastric  juice  would  only  make 
its  appearance  for  a  few  moments.     The  unwholesome  and 
indigestible  substance  would  remain  in  the   stomach  for  a 
time,  tending  to  cause  disease. 


282  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

116.  If  the  system  needed  food,  and  wholesome  food  were 
taken,  the  gastric   juice  would    continue  to  come  into  the 
stomach  for  from  5  to   30  minutes,  and  more  or  less  freely, 
according  to  the  requirement  of  the  system  for  food,  and  not 
according  to  the  amount  of  food  taken. 

117.  A  given  quantity  of  gastric  juice  could  only  digest 
a  given  quantity  of  food. 

If  therefore  more  food  were  taken  than  the  system  required,  the 
gastric  juice  which  would  be  formed,  would  not  be  sufficient  to  digest 
all  the  food  taken ;  and  not  only  would  some  of  the  food  remain  for 
a  time  undigested,  but  all  of  it  would  be  a  longer  time  in  digesting,  than 
a  proper  amount  would  have  been,  and  the  stomach  soon  become  de- 
ranged by  such  a  course.  A  person  should,  therefore,  eat  only  as  much 
as  the  system  requires. 

118.  When  the  system  was  diseased,  the  gastric  juice 
would  either  not  be  formed  at  all,  or  in  very  small  quantities, 
and  of  a  bad  quality  ;  and  food  taken  then,  though  the  system 
appeared  to  require  it,  would  be  imperfectly  digested,  and 
even  that  would  require  a  long  time.     When,  therefore,  a 
person  is  unwell,  it  will  be  useless  to  take  much  food,  to  say 
the  least,  as  it  cannot  be  digested. 

119.  Many  causes  increased  and  diminished  the  flow  of 
the  gastric  juice.     The  smell  of  food,  and  still  more  the  taste 
of  relished   food,  would  prepare  the  way  for  a  free  flow  of 
the  gastric  juice.     Lively  feelings  and  a  cheerful  disposition 
were  very  favorable  to  the  formation  of  a  large  quantity  of 
gastric  juice.     Spices  and  stimulating  food  or  drinks,  for  a 
few  times  increased  the  quantity,  but  after  a  little  time  di- 
minished as  much  as  they  had  increased  it.     Angry  feelings, 
a  melancholy  thought,  or  the  mind  engrossed  with  business, 
would  prevent  the  formation  of  gastric  juice,  though  food 
were  taken,  and  in  fact  required  by  the  body. 

This  shows  that  the  mind  has  a  powerful  influence  over  the  diges- 
tive process,  is  intimately  connected  with  the  stomach,  and  that  a  per- 
son who  would  live  long,  should  learn  to  love  wholesome  food,  eat  it 


SEC.  2.]  THE  STOMACH.  283 

with  a  relish,  preserve  an  agreeable  disposition,  and  devote  time  from 
his  business  to  eating,  and  avoid  brandies,  spices,  &c.,  which  for  the 
time  quicken  an  appetite  only  to  permanently  derange  the  stomach. 

120.  As  the  gastric  juice  is  formed  from  the  blood,  it  would  be  ex- 
pected that  the  flow  of  blood  would  be  increased  and  diminished  at  such 
times  as  the  gastric  juice  was  formed  in  large  or  small  quantities,  and 
this  Dr.  B.  found  to  be  the  case,  viz.,  the  same   causes  which  would 
cause  a  free  flow  of  gastric  juice  into  the  stomach,  would  cause  a  free 
flow  of  blood  through  the  stomach,  as  would  be  shown  by  the  color  of 
the  stomach,  which  when  it  was  healthy  and  empty,  was  a  yellowish  ash 
with  a  slight  pink  shade,  ripening  when  required  food  was  taken,  to  a 
deep  red  blush,  which  continued  while  the  gastric  juice  was  forming; 
but  when  that  was  produced  in  sufficient  quantity,  the  lively  color  of  the 
stomach  subsided. 

Feelings  of  anger  would  cause  the  stomach  to  become  pale  and  com- 
paratively bloodless. 

121.  As  such  an  active  circulation  of  the  "blood  is  re- 
quired about  the  stomach  that  the  needed  supply  of  gastric 
juice  may  be  formed,  it  will  not  be  proper  to  produce  an 
active  circulation  in  the  brain  by  intense  study  or  application 
to  business,  or  an  active  circulation  in  any  other  part  by 
energetic  exercise  of  it,  during  the  first  part  of  the  digestive 
process.     And  as  a  little  time  is  required  to  turn  the  circu- 
lation from  one  organ  which  has  been  very  active,  to  another 
which  has  not  been  in  action  for  some  hours,  a  short  period 
of  rest  should  be  taken  before  a  repast.* 

122.  If  it  be  necessary  to  eat  immediately  after  severe 
labor  or  mental  exercise,  or  if  it  will  be  necessary  to  labor 
or  exercise  immediately  after  eating,  it  is  evident  that  only  a 
small  repast  should  be  taken,  for  only  a  small  amount  of 
blood  can  be  allowed  to  the  stomach,  only  a  small  amount  of 
gastrice  juice  can  be  formed,  and  only  a  small  quantity  of 
food  can  be  digested. 

Many  people,  when  journeying  by  public  conveyance,  feeling  a  hearty 

*  No  man  would  think  of  feeding  his  horse  as  soon  as  he  stops,  when 
«n  a  journey.     Why  not  treat  himself  as  reasonably  ? 


284  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

appetite,  eat  much  food,  swallow  it  hastily,  and  finish  their  tour  with 
fatigue,  headache,  &c.  Lighter  repasts  will  enable  a  person  to  endure 
more,  and  at  the  end  of  the  journey,  after  a  few  hours'  rest,  the  appetite 
may  be  indulged  with  profit. 

123.  For  the  same  reasons,  very  much  food  should  in  no 
ordinary  cases  be  taken  before  retiring  to  sleep.  If  no  food 
have  been  taken  in  a  long  while  previous,  and  the  system 
seems  to  feel  the  need  of  some,  it  may  be  used,  but  very 
sparingly,  because  the  circulation  of  the  blood  is  not  active 
in  any  part  of  the  body  during  healthy  sleep. 

124.  The  circulation  of  the  blood  may,  however,  become  too  active,  as 
in  case  of  inflammation,  when  the  gastric  juice  will  be  no  longer  produced. 
The  blood  may  all  become  stagnant  in  the  bloodvessels,  which  contain 
perhaps  a  large  quantity  of  blood,  but  it  is  not  of  a  proper  quality ;  such 
a  state  is  called  congestion. 

125.  Owing  to  disease  or  some  other  cause,  the  gastric  juice  may  be 
formed  in  some  parts  of  the  lining  of  the  stomach,  but  not  in  others. 
Extensive  disease  affects  some  parts  of  the  stomach,  while  other  parts 
perform  their  duty  quite  well.     Canker  may  affect  certain  parts  of  the 
mouth  without  disturbing  the  rest,  so  it  may  the  stomach. 

126.  Besides  the  three  coats  already  mentioned,  some 
count  a  thin  layer  of  cellular  substance,  between  the  middle 
and  outer  coats,  as  a  fourth  and  a  similar  layer  between  the 
middle  and  inner  coat  as  the  fifth  coat  of  the  stomach. 

127.  The  stomach  has  two  openings.    One  through  which 
the  food  passes  into  the  stomach,  is  called  the  cesophagial, 
cardiac  (heart,  from  being  near  the  heart),  and  the  first  open- 
ing.    It  is-  situated  a  little  to  the  left  of  the  centre  of  the  body, 
and  about  one  third  the  distance  from  the  large,  towards  the 
small  extremity  of  the  stomach.     It  is  closed  by  the  contrac- 
tion of  the  lower  rings  of  the  oesophagus. 

128.  The  other  opening  is  several  inches  to  the  right  of 
the  centre  of  the  body,  and  nearly  on  a  level  with  the  first 
opening,  and  at  the  small  extremity  of  the  stomach.     It  is 

illed  the  pylorus  (porter),  because  it  opens  and  closes  to  allow 


SEC.  2.]  THE  STOMACH.  285 

food  to  pass  from  the  stomach  or  retain  it  there.  It  is  closed 
by  a  strong  band  of  muscular  fibres,  which  in  man  appear 
very  much  like  the  other  rings  composing  in  part  the  second 
stomach,  only  they  are  more  distinct,  and  in  some  animals,  for 
instance  the  turtle,  a  fold  as  it  is  called,  a  kind  of  "  tuck,"  (a 
lady  gave  me  the  expression,)  is  made  by  the  lining  ^f  the 
Stomach  at  the  pylorus.  In  this  fold  a  ring  of  muscular  fibres 
is  found.  An  approach  towards  this  is  sometimes  found  at 
the  pylorus  of  the  human  stomach.  -**  .iu 

129.  The  form  and  size  of  the  stomach  differs  in  differ- 
ent persons,  and  in  the  same  person  at  different  times.     The 
muscles  and  other  coats  of  the  stomach  distend  as  the  food 
is  received  at  any  time,  while  by  overfeeding,  the  utmost 
ordinary  capacity  of  the  stomach  can  be  very  much  in- 
creased.     The  general  form  of  the  stomach  when  mode- 
rately distended,  is  exhibited  by  the  various  figures  of  the 
stomach  ;  but  when  empty  it  becomes  small,  both  on  account 
of  the  contraction  of  its  muscles,  and  because  the  pressure 
of  the  other  organs,  and  the  muscles  of  the  abdomen  will 
crowd  it  into  a  small  space,  as  a  glove  might  be,   when  the 
hand  is  withdrawn. 

130.  The  position  of  the  stomach  is  seen  in  Lith.  PI.  3, 
Fig.  1.     It  is  supported  there  by  ligaments,  sometimes  called 
roots,  which  extend  from  the  upper  part  of  the  stomach,  that 
is,  the  part  between  the  openings  of  the  stomach,  to  the  back- 
bone, these  confine  the  upper  portion  and  the  openings  of  the 
stomach  very  nearly  to  one   position  ;   but  some  motion  is 
allowed  t3  them,  while  the  other  portions  of  the  stomach  are 
allowed  to  hang  downward,  project  forward,  or  be  pushed 
upward,  according  to  the  fulness  of  the  stomach,  and  the 
pressure  of  the  parts  surrounding  it  and  in  a  measure  sup- 
porting it.     The  position  of  the  stomach  very  much  depends, 
therefore,  on  whether  it  be  full  or  not ;  if  it  be  full,  it  occu- 
pies much  space,  if  it  be  empty,  but  little.     The  large  ex- 


280  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

tremity,  in  particular,  occupies  much  space  when  it  is  full. 
The  position  of  the  stomach,  full  or  empty,  changes  as  the 
breath  is  drawn  in  and  thrown  out ;  the  degree  of  change 
depending  on  the  fulness  of  the  breath. 

131.  We  may  now  give  attention  to  the  operations  taking 
place  in  the  stomach  when  wholesome  and  required  food  is 
taken.     1st.  The  stomach  distends  to  receive  it.     2d.  The 
redness  of  the  stomach  increases,  owing  to  the  increased  cir- 
culation of  blood  in  the  stomach.     3d.  The  gastric  juice 
makes  its  appearance.     4th.  The  muscles  of  the  large  ex- 
tremities begin  to  contract,  and  force  the  food  towards   the 
small  part  of  the  stomach,  mixing  it  together,  and  also  with 
the  gastric  juice.     5th.   The  temperature  of  the  stomach 
rises,  owing  to  the  increased  circulation  of  blood.     6th.  The 
food  thus  churned,  so  to  speak,  by  the  action  of  the  muscles 
of  the  stomach,  begins  to  be  acted  upon  by  the  gastric  juice, 
and  undergoes  that  change  commonly  called  digestion. 

132.  The  action  of  the  muscles  of  the  stomach  is  at  first 
slight,  but  in  a  short  time  increases,  and  continues  till  the 
food  passes  from  the  stomach,  though  it  grows  feeble  toward 
the  last.     Violent  exercise  of  any  other  part  of  the  body, 
and  depressing  states  of  the  mind,  check  it,  while  rest  and 
reasonable  vivacity  increase  it. 

133.  The  gastric  juice  continues  to  appear  in  the  stomach 
till  there  is  sufficient  to  digest  the  food,  if  too  much  be  not 
taken.     The  lively  red  appearance  of  the  stomach  continues 
during  the  same  time.     The  same  causes  as  check  or  in- 
crease the  action  of  the  muscles,  act  favorably  or  unfavor- 
ably on  the  formation  of  the  gastric  juice. 

134.  The  change  is  gradually  perfected  in  a  portion  of 
the   food  first ;    that  part  leaves  the  stomach   through   the 
pylorus,  while  the  rest  remains  to  pass  through  the  necessary 
change,  when,  little  by  little,  it  all  follows  the  same  way ', 
toward  the  last  it  passes  out  much  more  rapidly  than  at  first. 


SEC.  2.]  THE  STOMACH.  287 

135.  There  ia  something  singular  in  the  action  of  the  pylorus  in  this 
matter.     If  the  smallest  portion  of  well-digested  food  touches  the  inner  or 
stomach  surface  of  the  pylorus,  it  relaxes  and  allows  it  to  pass,  but  as  in- 
stantly contracts  when  any  undigested  portion  touches  its  inner  surface. 
If  also  any  unwholesome  food  have  been  taken,  it  will  closely  contract 
and  retain  it  in  the  stomach,  till  after  a  time  it  may  be  thrown  off  by 
vomiting,  if  that  be  best ;  if  not,  it  will  relax  and  allow  the  indigestible 
food  to  pass.     If  the  portion  of  indigestible  food  be  small,  such  as  seeds, 
&c.,  it  will  allow  it  to  pass  rather  than  compel  the  stomach  to  cast  off  a 
large  amount  of  wholesome  food.    Jn  early  life,  when  it  might  be  ex- 
pected that  inexperienced  childhood  would  eat  too  much,  and  also  un- 
wholesome food,  the  pylorus  is  very  apt  to  refuse  undigested  food  to  pass 
its  portals. 

136.  It  cannot  be  that  this  action  of  the  pylorus  is  controlled  by  the 
mind  ;  but  it  must  be  dependent  upon  the  influence  of  the  nervous  system 
of  organic  life.     Its  regularity  must  therefore  depend  upon  the  general 
health  of  the  body,  and  it  must  become  irregular  when  the  health  is  de- 
ranged. 

We  may  now  give  our  attention  to  the  food,  the  changes  it  under- 
goes in  the  stomach,  and  what  facilitates  these  changes. 

1st,   The  Chemical  Nature  of  the  Food. 

137.  The  food  must  be  in  part  composed  of  those  sub- 
stances, elements,  or  compounds,  which  are  found  in  the  body. 

The  bones,  for  instance,  are  composed  of  lime,  and  they  cannot  be 
kept  in  good  condition  without  lime  be  eaten  in  certain  proportions. 
But  the  lime  which  is  eaten  for  the  good  of  the  bones,  must  be  combined 
with  certain  other  things  before  it  is  taken  into  the  mouth.  For  if  lime 
should  be  put  in  water  and  drank,  or  in  any  way  swallowed  into  the  sto- 
mach, the  bones  would  not  be  benefited.  Oxygen  and  hydrogen  united 
in  certain  proportions,  form  water  ;  but  if  a  person  should  force  oxygen 
and  hydrogen  into  the  stomach,  it  could  not  form  drink  of  them.  A  bit 
of  fat  is  composed  of  oxygen,  carbon,  and  hydrogen.  If  these  substances, 
not  combined,  should  be  taken  into  the  stomach,  it  could  not  form  fat  of 
them. 

138.  Food,  therefore,  must  not  only  be  in  part  composed 
of  the  same  elements  as  the  body,  but  these  elements  must 
be  combined  in  a  certain  way. 


288  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

To  combine  them  in  certain  ways,  plants  are  needed.  In  them,  there- 
fore, strictly  speaking,  the  first  process  of  digestion  is  performed.  The 
sugar-cane  has  its  roots  in  the  ground,  its  stalk  and  leaves  in  the  air,  and 
both  roots  and  leaves  are  refreshed  with  water.  From  the  air,  earth  and 
water,  it  selects  the  ingredients  of  sugar,  viz.  carbon,  oxygen,  and  hy- 
drogen; and  combining  them  in  a  proper  manner,  sugar  is  the  result. 
The  sugar  taken  into  the  mouth  is  crushed  and  mixed  with  saliva,  then 
swallowed  into  the  stomach,  where  it  undergoes  a  change  which  is  usu- 
ally called  the  first  process  of  digestion.  It  then  passes  on,  and  at  last 
is  separated  into  its  original  elements  or  an  approach  towards  them  ; 
for  instance,  it  may  be  into  oxygen,  and  carbon,  and  hydrogen  ;  or  the 
oxygen  and  hydrogen  may  remain  united,  if  in  proper  proportions,  forming 
water,  and  the  carbon  may  be  left  by  itself,  or  the  carbon  and  hydrogen 
may  be  left  united,  and  the  oxygen  released.  Our  knowledge  of  the 
changes  is  not  very  definite  ;  but  when  the  substance  serves  its  use,  the 
combination  of  its  elements  is  broken  up,  and  they  are  ready  to  be  cast 
out  of  the  system,  and  be  again  combined  with  each  other  in  plants,  and 
again  eaten. 

139.  Thus  it  is  with  all  the  articles  used  by  the  system.     They  are 
composed  of  the  simple  elements,  as  they  are  called,  united  together,  and 
forming  what  are  called  the  compound  elements  of  food.    The  compound 
elements  are  formed  in  plants  from  the  simple  elements,  called  also  ulti- 
mate elements.  When  a  creature  eats  these  plants,  it  eats  the  compound 
elements,  called  also  proximate  elements,  and  the  compound  elements 
become  parts  of  its  own  body :  if  man  or  other  animals  eat  the  flesh  of 
a  creature,  he  or  they  eat  the  compound  elements  of  which  the  creature's 
body  was  composed,  and  which  were  obtained  by  the  creature  from  some 
plant.     The  compound  elements  may  thus  pass  along,  from  the  plant  to 
an  animal,  and  from  animal  to  animal,  till  at  last  in  the  body  of  some 
one  they  are  used,  and  become  decomposed  into  their  simple  elements, 
when  the  office  of  the  plant  will  be  again  required. 

140.  The  compound  elements  are  rarely  found  alone  in  the  plant. 
When  the  sugar  is  pressed  out  of  the  cane,  there  is  a  great  deal  of  husk 
Jeft ;  when  starch  is  taken  from  a  potato,  there  is  much  substance  left. 
Those  animals  therefore,  which  live  upon  plants,  will  require  an  appara- 
tus to  separate  the  compound  elements  in  the  plant  from  the  other  por- 
tions of  the  plant,  which  as  food  are  of  no  use  to  the  animal.     For 
instance,  an  animal  eating  the  sugar-cane  must  be  supplied  with  an 
apparatus  for  extracting  the  sugar  and  any  other  substance  that  may  be 
of  ua«  to  the  animal.     Man  grinds  the  cane  in  a  mill,  and  by  the  exer- 


SEC.  2.]  THE  STOMACH.  289 

else  of  his  ingenuity,  contrives  a  press  to  extract  the  juice,  but  the  ox 
must  grind  the  cane  in  his  mouth,  and  extract  the  sugar  in  his  stomach. 

141.  Those  animals,  therefore,  which  live  upon  plants  directly,  will 
require  a  more  extensive  apparatus  than  those  animals  living  upon  the 
flesh  of  other  animals.     Those  animals  which  live  upon  plants,  or  those 
parts  of  plants  which  contain  comparatively  a  small  quantity  of  the  com- 
pound elements,  would  require  a  more  extensive  digesting  apparatus 
than  those  animals  intended  by  nature  to  live  upon  those  plants,  or  parts 
of  plants,  containing  a  comparatively  larger  amount  of  the   compound 
elements.  ^ 

142.  Thus  it  is  found  that  the  digestive  organs  of  animals  living  upon 
plants,  such  as  grass,  grains,  fruits,  &c.,  have  very  extensive  digestive 
organs.     The  cow  and  sheep  have  four  stomachs,  &e.,  while  those  ani- 
mals like  the  tiger,  &c.,  which  live  upon  other  animals,  have  very  simple 
digestive  organs ;  while  those  living  upon  the  grains  or  seeds  of  plants, 
have  a  less  extensive  digestive  apparatus  than  those  living  upon  all  parts 
of  plants. 

143.  The  next  question  is  this:  Does  the  system  select 
from  the  food  eaten,  all  the  compound  elements  it  contains,  or 
only  that  portion  of  them  the  system  at  the  time  requires  ? 

This  is  uncertain.  The  probability  is,  that  sometimes  it  does,  and 
sometimes  it  does  not.  The  system  seems  to  have  a  strong  inclination 
to  lay  up  a  store  of  fat  if  proper  food  be  eaten,  especially  in  the  fall  of 
the  year,  and  this  not  as  a  covering  for  the  body  merely,  for  it  is  stored 
away  in  the  internal  parts  of  the  body  as  well  as  directly  under  the  skin ; 
but  how  much  of  the  other  compounds  it  will  take  from  the  food  against 
the  future  wants  of  the  system,  is  uncertain ;  doubtless  some,  but  not 
much. 

144.  Food  may  then  be  divided  into  two  kinds ;   one  the 
useful   part,   composed   of  compound   elements,   the   other, 
useless  or  waste,  and  consisting  of  those  parts  of  the  food 
not  composed  of  compound  elements,  and  such  of  the  com- 
pound elements  as  are  not  wanted  (if  there  be  any  such)  by 
the  system. 

Whether  man  should  partake  of  both  kinds  will  be  discussed  when 
speaking  of  the  second  stomach,  as  both  kinds  require  the  same  treatment 
till  they  arrive  in  the  second  stomach. 

13 


290  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

2d.  Preparation  of  Food  for  the  Stomach. 

145.  As  these  compound  elements  must  be  carried  into 
every  part  of  the  body  through  vessels  exceedingly  small,  it 
is  necessary  that  they  should  be  reduced  to  a  very  finely 
divided  state,  for  which  purpose  the  teeth  have  been  pro- 
vided   in    the    first    place.      These,    therefore,    should    be 
thoroughly  used. 

Dr.  Beaumont  testifies,  that  food  was  a  long  time  in  digesting  in  the 
stomach,  except  it  were  well  chewed.  Indeed,  if  the  food  were  swal- 
lowed or  put  into  the  stomach  in  large  pieces,  it  would  remain  there  so 
long  as  to  cause  disease  of  the  stomach.  He  frequently  tried  the  experi- 
ment of  hanging  meat,  &c.,  in  the  stomach  of  St.  Martin,  and  always 
found  that  if  such  experiments  were  tried  for  several  days  in  succession, 
inflammation  of  the  stomach  would  appear.  Persons  should  not,  there- 
fore, hurry  the  food  into  the  stomach,  but  take  time  to  enjoy  it ;  and  if 
there  be  but  little  time  to  eat,  then  «at  but  little,  but  do  it  well.  Chil- 
dren should  be  taught  not  to  swallow  half-chewed  food,  both  by  example 
and  precept. 

146.  If  the  food  be  thoroughly  chewed,  it  will  also  be 
well  mixed  with  saliva — an  important  thing,  as  by  softening 
the  food,  if  nothing  more,  it  causes  the  juices  of  the  stomach 
to  act  easily  upon  the  food. 

147.  Food  should  also  be  such  that  it  can  be  properly 
chewed  and  mingled  with  the  saliva.     Such  things  as  are 
not  acted  upon  at  all  by  the  teeth,  should  not  be  eaten ; 
and  much  care  must  be  taken  in  eating  radishes,  cucumbers, 
raw  potatoes,  &c.,  that  they  be  thoroughly  chewed,  other- 
wise Dr.  B.  found  they  would  not  be  readily  digested.    Food 
should  also  be  cooked  in  such  a  manner,  that  it  can  easily  be 
chewed,  and  will  easily  be   saturated  with   saliva.      Rare 
baked  or    boiled  potatoes,  for  instance,  are  very  unwhole- 
some ;  solid  bread,  heavy  pastry  in  which  there  is  much  fat 
especially,  must  be  very  unwholesome.     Hard-boiled  eggs 
are  bad ;  indeed,  the  food  should  always  be  prepared  so  as 


SEC.  2.]  THE  STOMACH.  291 

to  be  light,  easily  chewed,  and  easily  saturated  with  the 
juices  of  the  mouth  and  stomach.* 

3d.  The  Quantity  of  Food. 

148.  This  depends,  in  the  first  place,  upon  the  health  of 
the  system. 

As  heretofore  shown,  there  cannot  be  a  healthy  circulation  of  blood 
about  the  stomach,  nor  gastric  juices  properly  formed,  when  the  system 
is  unhealthy.  Under  such  circumstances  it  would  be  useless,  therefore, 
to  take  food  even  if  the  system  needed  it.  In  such  a  case,  the  proper 
way  is  to  treat  the  system  in  such  a  manner  that  it  will  not  need  much 
if  any  food,  viz.,  it  must  not  be  vigorously  exercised  or  much  exposed  to 
cold.  If  exercise  be  absolutely  necessary,  the  system  can  certainly  be 
protected  by  extra  clothing,  but  extra  food  must  not  be  used ;  for  how 
can  the  system  when  unwell  accomplish  the  double  task  of  taking  the 
exercise  and  digesting  food?  It  is  singular  that  a  person  does  not 
always  reflect,  that  if  the  system  be  feeble  it  cannot  digest  food ;  that 
when  it  exhausts  him  to  "  sit  up  "  or  move  about,  the  powers  of  his  body 
are  certainly  not  sufficient  to  the  task  of  preparing  food  for  use.  Let 
this  be  considered  a  rule  of  the  highest  importance — WHEN  UNWELL,  EAT 
BUT  LITTLE  ;  the  less  the  better.  Many  a  fit  of  sickness  will  thus  be 
avoided. 

149.  In  the  second  place,  the  quantity  of  food  should 
depend,  if  the  system  be  healthy,  on  the  kind  of  food  eaten. 

If  the  food  contain  much  waste  substance,  a  greater  quantity  will  be 
required  to  satisfy  the  wants  of  the  system.  If  the  system  require  food 
to  warm  it,  while  the  kind  of  food  eaten  contains  few  of  the  compound 
elements  adapted  to  that  purpose,  a  large  quantity  of  food  is  required. 
Thus  by  not  eating  the  right  kind  of  food  a  person  may  derange  his 
system,  as  he  compels  it  to  digest  a  larger  quantity  of  food  than  its 
powers  can  endure  ;  as  it  is  easily  conceived  that  the  food  may  be  of 
such  quality,  that  the  powers  of  the  system  would  be  exhausted,  before  it 
could  digest  so  large  a  quantity  of  food  as  would  contain  the  ingredients 
required  for  its  use. 

150.  In  the  third  place,  the  quantity  of  food  should  de- 

*  Since  the  saliva  is  so  important  for  the  digestion  of  the  food,  those 
people  must  do  themselves  much  harm,  who  by  using  tobacco,  prevent 
the  stomach  from  receiving  its  proper  portion. 


292  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

pend,  if  the  system  be  in  health  and  proper  food  eaten,  upon 
the  amount  of  exercise  taken. 

As  exercise  wears  out  the  system,  viz  ,  causes  the  compound  ele- 
ments to  be  decomposed  into  simple  elements,  new  material  must  be 
eaten  in  corresponding  ratio. 

151.  In  the  fourth  place,  if  proper  food  be  taken  in  a 
healthy  state  of  the  system,  its  quantity  should  depend  upon 
the  growth  of  the  person. 

Wnen  the  body  is  growing,  it  must  receive  in  the  form  of  food,  the 
ingredients  by  which  to  increase  its  size.  If  these  do  not  exist  in  the 
food,  or  if  so  much  exercise  be  taken  that  all  the  usable  ingredients 
of  the  food  are  required  to  supply  the  place  of  the  worn-out  substance 
of  the  body,  the  body  cannot  increase  in  size  ;  hence  poor  food  and  hard 
labor  will  check  the  growth  of  the  young,  especially  as  the  body  must  use 
all  the  useful  parts  of  the  food  in  fitting  the  body  to  endure  the  labor  that 
is  inflicted  upon  it.  Hence  the  curse  of  those  manufacturing  establish- 
ments in  the  old  world,  where  children  are  necessarily  employed  and 
half-fed,  to  make  the  products  of  labor  cheap.*  If  the  system  be  using 
the  ingredients  of  the  food  in  increasing  the  size  of  the  body,  it  would  be 
natural  to  suppose  the  body  would  soon  be  weakened  by  active  exercise, 
and  its  parts  comparatively  weak  and  imperfectly  formed.  Much  rest 
is,  therefore,  needed  at  such  times. 

In  this  connection,  an  explanation  may  be  given  of  the  cause  for 
fishes  being  supported  in  a  common  fish-globe,  the  water  being  changed 
once  in  a  day  or  two.  The  fish  has  but  little  opportunity  to  exercise, 
and  of  course  can  require  but  little  food  to  repair  itself ;  if  plenty  of  food 
of  a  nourishing  quality  be  given  to  it,  the  fish  will  grow  most  wonder- 
fully. 

152.  In  the  fifth  place,  the  quantity  of  food  should  de- 
pend, if  the  body  be  healthy  and  the  food   proper,  upon 

*  It  is  to  be  hoped,  as  the  laws  have  already  done  something  to 
remedy  in  this  country  the  growing  evil,  that  ere  long  it  will  be  seen 
that  the  good  of  community  and  the  cause  of  humanity  demand  the 
curtailment  of  the  tyrannical  power  exerted  by  some  parents,  who,  to 
support  themselves  in  the  lowest  kinds  of  dissipation  and  idleness,  make 
slaves  of  their  children — their  own  flesh  and  blood — and  confine  them  to 
labor  under  the  most  unfeeling  taskmasters,  the  whole  weary  day ;  till 
the  life,  the  ambition,  the  pride  of  youth  become  stupidity,  submissive- 
ness,  and  indifference. 


SEC.  2.]  THE  STOMACH.  293 

\viiether  it  be  desirable  or  not  to  increase  the  fat  in  the 
system. 

It  will  be  impossible  to  "  fatten "  man  or  animals,  if  there  be  not 
more  food  taken  than  is  sufficient  to  supply  the  nourishment  required  by 
the  daily  exercise  of  the  body,  and  to  keep  the  body  warm  ;  nor  can  the 
fat  of  the  body  be  formed,  if  the  powers  of  the  system  be  exhausted  in 
their  efforts  to  warm  and  repair  the  body  ;  for  those  things  must  be  done 
before  fat  will  be  deposited.  It  is  therefore  evident,  that  little  exercise 
and  want  of  exposure,  and  much  food,  will  tend  to  increase  the  fat  of  an 
animal ;  while  over-exercise  or  great  exposure  to  cold,  or  want  of  food, 
will  prevent  the  deposit  of  fat.  A  horse  over-driven  will  not  grow  fat, 
nor  will  an  animal  turned  out  to  the  weather,  as  is  evident  in  the  case 
of  cows  that  farmers  sometimes  allow  to  range  all  winter.  It  is  however 
to  be  noticed,  that  proper  exercise  and  exposure  tends  to  increase  an  ap- 
petite, and  thereby,  if  not  in  extreme,  help  fatten  an  animal.  The  state 
of  the  mind  has  an  influence  on  the  formation  of  fat. 

153.  In  the  sixth  place,  proper  food  being  taken  by  a 
healthy  body,  the  quantity  should  depend  on  the  exposure  to 
the  cold. 

As  an  animal  depends  for  heat  upon  its  food  on  the  one  hand,  of 
course  the  amount  of  food  should  be  proportionate  to  the  heat  to  be  pro- 
duced. If  a  horse  be  provided  with  a  blanket,  he  requires  less  food  to 
keep  him  warm,  because  the  blanket  prevents  the  heat  from  passing  away 
rapidly.  A  warm  and  protective  stable  has  a  like  effect.  So  will  it  be 
witk  other  animals.  Cows  which  are  "  kept  at  the  stack,"  that  'is,  out 
of  doors,  eat  all  winter  very  heartily,  yet  do  not  better  their  condition  ; 
for  all  they  can  eat  is  used  in  their  bodies  to  produce  heat  required  the 
whole  while.  It  is  wise,  therefore,  to  shelter  animals.  In  this  connec- 
tion it  may  also  be  noticed,  that  the  natural  heat  of  some  animals  is  much 
greater  than  that  of  others,  and  of  course  those  animals  of  the  highest  natu- 
ral temperature,  require  the  most  food.  Thus  fishes,  which  are  naturally 
of  a  low  temperature,  require  but  little  food  to  produce  heat,  and  if  much 
food  of  a  heat-producing  tendency  be  given  them,  they  will  become  fat, 
for  they  cannot  use  it  for  any  other  purpose.  Fish  therefore  are  the  most 
easily  fattened  of  any  animals.  Taking  into  consideration  what  was 
said  in  a  former  paragraph,  it  will  be  evident  that  fish  are  the  most  pro- 
fitable animals  that  can  be  raised,  and  the  reason  is  also  seen  why  there 
should  be  such  multitudes  of  fish,  viz.,  they  require  but  very  little  food, 


294  THE  DIGESTIVE  OR&ANS.  [CHAP.  I. 

comparatively  speaking.  The  water  in  which  they  live  is  nearly  of  the 
same  weight  as  the  fish  ;  it  therefore  supports  them  without  effort  on 
their  part — they  are  not  a  restless  animal,  and  when  they  do  move,  it  is 
with  slight  effort ;  they  wear  out  their  bodies  but  little  therefore.* 

154.  In  the  seventh  place,  the  quantity  of  food  should 
depend  upon  how  thoroughly  the  digestive  organs  separate 
the  compound  elements  from  the  waste  portion  of  the  food. 

This  depends  upon  the  nature  of  the  food — for  some  kinds  are  much 
easier  of  thorough  digestion  than  others — upon  how  the  food  is  cooked, 
upon  how  thoroughly  the  food  is  chewed  and  mixed  with  the  saliva, 
upon  the  nature  and  health  of  the  digestive  organs,  upon  the  nature  tnd 
health  of  the  nervous  system,  and  upon  the  mind.  Why  the  digestive 
organs  of  one  person  should  refuse  to  act  thoroughly  upon  a  kind  of  food 
very  easily  digested  by  another,  is  not  known;  but  such  is  the  fact. 
When  the  digestive  organs  are  diseased,  they  will  digest  some  articles 
readily,  which  they  abhor  when  healthy.  That  these  things  depend  much 
upon  the  mind  and  nervous  system,  is  evident  from  various  facts.  Said 
a  friend,  when  riding  past  some  quarrelsome  animals  which  were  also 
very  lean,  "  they  have  such  dispositions  they  can  never  become  fat."  It 
is  so  with  man.  It  may  be  considered  almost  a  certain  thing,  that  a  fat 
person  is  pretty  good-natured,  and  has  not  a  very  active  mind.  A  con- 
stantly active  mind,  especially  a  fretted  disposition,  does  not  allow  the 
stomach  to  receive,  for  a  sufficient  length  of  time,  those  nervous  influ- 
ences necessary  for  a  perfect  digestion  of  food.  Active  mental  and 
physical  exercise,  with  a  diminished  supply  of  food,  will  soon  show  their 
effects  on  most  persons.  Yet  there  are  certain  persons  so  constituted, 


*  There  is  but  little  outlay  in  preparing  to  keep  them  ;  a  tub,  barrel, 
or  trough,  with  a  very  small  stream  of  running  water,  or  a  mere  hole 
dug  in  the  ground,  will  be  sufficient  for  a  colony  of  fish  of  the  most  de- 
licious flavor,  and  the  scraps  from  a  poor  man's  table  will  all  be  profita- 
bly used  by  these  animals,  and  returned  almost  pound  for  pound.  Fish 
will  be  much  more  profitable  than  swine,  the  meat  being  more  wholesome 
and  more  cheaply  obtained.  In  any  city  supplied  with  running  water, 
young  fish  might  be  kept  by  a  family  with  scarcely  any  expense,  and 
fattened  and  grown  till  they  would  furnish  a  good  repast  for  the  table. 
It  is  not  necessary  that  the  water  should  run  constantly  through  where 
the  fish  are  kept ;  it  is  sufficient  that  the  water  be  changed  once  or  twice 
per  day,  or  once  in  two  or  three  days,  according  to  the  size  of  the  reser.- 
voir  and  the  number  of  fish  in  it.  It  would  seem  to  be  a  profitable  un- 
dertaking for  a  person  to  raise  fish  for  the  city  markets. 


SEC.  2.]  THE  STOMACH.  295 

that  circumstances  in  the  slightest  degree  favorable  will  develop  fat. 
Active  mental  exercise  will  also  prevent  the  perfect  digestion  of  that 
kind  of  food  which  is  adapted  to  nourish  the  muscles ;  and  not  only 
do  wrinkles,  but  a  spareness  of  the  muscles  exhibit  a  careworn  person. 

155.  In  the  eighth  place,  with  the  foregoing  considera- 
tions in  mind,  the  quantity  of  food  should  be  governed  by  the 
appetite. 

This  should  be  satisfied,  but  not  satiated.  To  know  when  the 
appetite  is  satisfied,  the  food  should  be  eaten  in  accordance  with  the 
intentions  of  nature,  viz.,  it  should  be  thoroughly  chewed  and  mixed 
with  the  saliva,  then  it  will  be  slowly  swallowed  into  the  stomach  and 
the  appetite  gradually  suspended.  But  if  the  food  be  hurried  into  the 
stomach,  it  may  be  filled  with  food  indigestible,  perhaps,  and  all  of 
which  would  not  be  needed  even  if  it  could  be  digested. 

156.  The  cause  of  the  sensation  of  hunger  acts,  of  course,  through 
the  nervous  system  upon  the  mind.     If,  therefore,  diseases  produce  a 
similar  state  in  the  nerves  to  that  caused  by  some  part  or  parts  of  the 
body  when  food  is  required,  the  sensation  will  be  the  same,  but  it  will 
not  be  satisfied  by  eating  food,  as  want  of  food  is  not  the  cause  of  the 
sensation.     Thus,  sometimes  persons  have  what  they  call  a  "  headache 
appetite,"  or  "  hungry  headache,"  but  in  such  cases  food  must  not  be 
eaten. 

157.  On  the  other  hand,  diseases  may  produce  such  a  state  of  the 
nervous  system  that  the  wants  of  the  body,  in  respect  to  food,  cannot 
produce  any  sensation  of  hunger.     In  this  case  the  appetite  must  be 
aroused  by  some  means.     The  natural  causes  which  arouse  the  appetite 
are  exercise  and  exposure  to  the  cold.     Gentle  exercise  and  slight  ex- 
posure, for  instance  a  short  and  easy  ride  in  the  open  air,  are  to  be  first 
tried  ;  if  the  effect  is  desirable,  they  are  to  be  gradually  increased.     If 
they  do  not  succeed,  various  medicines  may  be  resorted  to.     But  before 
exercise  and  exposure,  and  much  more  before  medicines  be  tried,  there 
must  be  great  certainty  that  the  system  needs  and  is  capable  of  enduring 
them. 

In  the  spring  of  the  year,  for  instance,  and  when  confined  to  the 
house  by  various  causes,  there  ought  not  to  be  a  hearty  appetite  ;  and 
many  a  person  has  reproduced  disease  from  which  he  was  recovering, 
by  not  being  sufficiently  careful  about  taking  exercise  and  making  ex- 
posure to  the  cold.  It  is  always  best  to  err  on  the  safe  side,  and  it  is 


293  THE  DIGESTIVE  ORGANS.  [CHAP,  I. 

seen  not  to  be  so  easy  a  thing  to  give  good  advice  as  might  at  first  be 
supposed. 

158.  When  a  person  first  feels  unwell  or  has  been  so  but 
a  very  short  time,  there  is  one  rule  to  be  always  observed. 
If  there  be  no  appetite  let  no  food  be  used  till  appetite  occur, 
even  if  it  do  not  for  days  or  weeks ;   but  commencing  with 
total  abstinence,  24  hours  will  usually  restore  to  health.     At 
the  same  time  take  but  little  if  any  exercise,  and  clothe  warmly 
if  compelled  to  go  out.     If  there  be  an  appetite,  but  not  strong,. 
a  small  quantity  of  easily  digested  food  maybe  taken;  but 
usually  it  will  be  more  judicious  not  to  eat  any.     If  there  be 
a  hearty,  hankering  appetite,  when  a  person  is  unwell  or 
sick,  or  when  well  if  there  be  an  appetite  for  evidently  un- 
wholesome things,  chalk,  clay,  slate  pencils,  spruce   gum, 
alcoholics,  tobacco,  &c.,  they  ought  to  be  utterly  refused. 
They  will  only  make  a  bad  matter  worse;  the  desire  for 
them  is  produced  by  a  wrong  state  of  the  nervous  system,  that 
produces  these  false  appetites. 

159.  If  an  appetite  be  produced  immediately  after,  or  be- 
fore active  mental  or  physical  exercise,  it  should  be  gratified 
sparingly. 

The  exercise  which  has  been  or  is  to  be,  will  render  the  system  unfit 
to  digest  a  large  quantity  of  food,  though  it  may  be  required.  Appe- 
tite is  not  apt  to  occur  immediately  after  extraordinary  exercise.  A 
horse  will  not  usually  eat  as  soon  as  put  in  the  stable  after  a  hard  drive  ; 
but  he  should  not  have  food  then,  if  he  will  eat  it ;  neither  ought  man  to 
eat  food  in  a  corresponding  case.  If  appetite  occur  just  before  retiring  to 
sleep,  it  should  not  be  gratified,  except  the  body  has  been  a  very  long 
time  without  food,  when  of  two  evils,  the  least  will  usually  arise  from 
eating  sparingly. 

4th.    The  Quality  of  Food. 

160.  This  may  be  first  considered  in  respect  to  its  tem- 
perature.    In  infancy,  nature  has  intended  the  food  should 


SEC.  2.]  THE  STOMACH.  297 

be  taken  at  nearly  the  temperature  of  the  throat.  Ninety- 
eight  degrees  may  be  considered  as  the  healthful  point. 

If  children  are  fed  artificially,  it  is  an  extremely  important  thing  to 
have  the  temperature  regulated  by  some  better  criterion  than  the  lips 
of  a  person  whose  sensations  are  affected  by  sd  many  circumstances  as 
act  upon  the  most  healthy.  In  ^very  family  a  thermometer  should  be 
considered  as  a  requisite,  and  food,  viz.,  milk  for  a  young  child,  should  be 
warmed  by  setting  the  dish  containing  it  in  water,  and  never  allowing 
it  to  rise  in  temperature  above  98  degrees  by  the  thermometer ;  for  a 
dish  of  milk  set  directly  upon  the  stove  or  coals,  frequently  will  burn  the 
milk  at  the  sides  or  bottom  of  the  dish,  and  often  the  milk  is  allowed 
even  to  boil.  But  heating  milk  above  100  degrees  injures  it  by  altering 
its  nature  to  a  degree.  To  giving  a  child  food  of  an  unnatural  tempera- 
ture, and  pouring  it  into  the  mouth  with  a  spoon,  &c.,  so  that  it  cannot 
be  mingled  with  the  saliva  before  it  is  swallowed,  may  be  traced  the 
cause  of  many  fits,  convulsions,  and  diseases  which  are  met  with  in 
childhood,  and  which  lay  the  foundation  for  disease  in  after  life. 

161.  After  the  period  of  infancy,  nature  has  evidently  intended  that 
the  food  should  be  used  of  a  temperature  more  irregular ;  but  yet  she  has 
given  an  instinct  to  animals  to  drink  near  to  the  spring  in  winter  and  far 
from  it  in  summer.  The  food  of  animals  is  not  a  good  conductor  of  heat, 
and  produces,  therefore,  no  powerful  sensation  when  taken  into  the 
mouth,  and  being  chewed  is  not  cold  when  swallowed.  In  cold  climates 
the  drink  of  animals  is  necessarily  cold,  but  in  cold  weather  little  drink 
is  required,  without  an  animal  has  been  used  unnaturally,  and  all  expe- 
rienced persons  ar«  aware  that  it  will  not  be  proper  to  allow  animals, 
if  tired,  to  drink  cold  water  plentifully  either  in  summer  or  winter.  Iced 
water,  cream,  and  desserts  are  fruitful  sources  of  dyspepsia.  It  may 
therefore  be  argued,  that  food  should  not  be  taken  either  very  cold  or 
very  warm,  either  in  winter  or  summer. 

162.  Another  argument  in  favor  of  the  same  idea  may 
be  advanced,  viz.,  that  very  hot  or  cold  articles  act  injurious- 
ly upon  the  teeth,  and  what  affects  one  part  of  the  body  inju- 
riously, affects  every  other  part  in  a  similar  manner. 

163.  The  effect  of  low  temperatures  will,  however,  vary  in  persons 
of  different  constitutions,  as  will  be  seen  by  noticing  the  effect  of  cold 
upon  any  part  of  the  body.  If  the  hands  be  thrust  into  cold  water,  or 
cold  water  be  dashed  upon  any  part  of  the  body  in  health,  or  if  the  face 

13* 


298  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

of  ft  healthy  person  be  exposed  to  the  cold  air,  a  glow  or  flush  will  be 
produced,  by  an  increase  of  the  circulation  of  blood  through  the  part, 
that  it  may  be  kept  warm.  If  a  person  be  very  feeble,  the  glow  is  not 
produced,  because  the  system  has  not  power  to  increase  the  circulation 
of  blood.  The  same  things  occur  in  the  stomach.  If  a  person  be  suffi- 
ciently healthy,  there  will  be  an  increased  circulation  of  the  blood  about 
the  stomach,  and  as  the  increased  quantity  of  blood  is  required  in  the 
formation  of  gastric  juice,  the  cold  facilitates  digestion.  But  when  there 
is  inflammation  of  any  part  of  the  body,  for  instance  the  brain,  physicians 
are  in  the  habit  of  applying  cold  continuously,  for  instance  a  bladder  of 
ice,  tor  the  purpose  of  lessening  the  circulation.  Thus  will  it  be  with  the 
stomach,  even  of  the  most  healthy  ;  the  application  of  cold  continuously 
will  diminish  the  circulation,  and  retard  digestion,  and  Dr.  Beaumont  tes- 
tifies that  he  has  noticed  the  process  delayed  for  an  entire  hour,  by  the  re- 
ception of  a  large  quantity  of  cold  water. 

164.  The  injurious  effect  of  cold  upon  the  stomach  will 
depend  upon  the  quantity  of  cold  articles  taken  ;  upon  the 
natural  constitution — for  some  constitutions  bear  cold  much 
better  than  others,  and  recover  from  its  action  quicker ;  upon 
the  health  of  the  person — for  a  feeble  person  cannot  recover 
from  the  effects  of  cold  as  the  same  person  could  if  well ; 
upon  the  age  of  the  individual — for  infants  and  elderly  peo- 
ple cannot  bear  cold  as  those  in  the  prime  of  life  ;  and  upon 
the  exhaustion  of  the  system — for  when  the  system  is  ex- 
hausted, either  by  labor,  by  exposure  to  heat  or  cold,  by 
watching,  or  fasting,  it  cannot  increase  the  circulation  in  any 
of  its  parts  to  a  remarkable  degree. 

165.  As  cold  articles  taken  into  the  stomach  are  warmed 
by  the  circulation  of  blood,  and  as  muscular  exercise  in- 
creases the  circulation  in  every  part,  it  should  always  be 
used  when  any  chill  is  felt  at  the  stomach  after  taking  any 
thing  cold. 

In  brief,  therefore,  cold  articles  should  not  be  taken  into  the  stomach 
when  the  body,  from  any  cause,  is  not  well  able  to  spare  the  heat  for. 
warming  them.  This  will  be  determined  by  any  chill  felt  in  the  region 
of  the  stomach,  though  it  is  well  to  exercise  a  sound  judgment  before 


SEC.  2.]  THE  STOMACH.  299 

trying  the  experiment.  It  is  not,  therefore,  wrong  to  take  cold  articles 
into  the  stomach  because  a  person  is  "  warm,"  but  because  he  is  ex- 
hausted. As  the  same  cause  that  made  the  body  warm  has  produced 
exhaustion,  it  has  been  usually  noticed  that  cold  articles  taken  when  the 
body  was  warm  produced  harm.  If,  however,  the  same  exhaustion  should 
exist  when  a  person  was  cold,  it  would  be  so  much  the  worse  ;  so  that  in 
fact  it  is  better  for  a  person  to  be  warm  when  exhausted,  and  liable  to 
drink  or  eat  cold  articles.  If  a  man  rest  himself,  or  his  animal,  after 
exertions  before  taking  cold  articles,  it  is  not  to  cool  himself  or  the  ani- 
mal, but  to  rest  the  system,  so  that  when  the  drink  is  taken  the  body  will 
have  power  to  warm  it. 

166.  Cold  water  is  therefore  the  best  beverage  for  some  ; 
and  for  some,  warm  but  unstimulating  drinks,  especially  in 
winter,  are  better. 

167.  It  is  certain,  on  the  other  hand,  that  nature  never 
intended  hot  food  should  be  used  by  man. 

For  she  has  made  it  exceedingly  unpleasant  to  receive  it  into  the 
mouth,  which,  in  many  respects,  is  a  very  good  outpost  to  warn  of  danger 
approaching  the  stomach,  arid  though  it  may  sometimes  be  a  very  good 
plan  to  assist  in  warming  the  body  by  the  use  of  heat-giving  articles  of 
food,  yet  the  continued  use  of  them  above  the  temperature  of  the  body, 
has  been  often  found  by  experience  to  weaken  the  digestive  organs  in  a 
remarkable  degree,  preventing  a  healthy  circulation  of  blood  about 
the  stomach,  and  of  course  the  formation  of  a  proper  supply  of  gastric 
juice. 

168.  The  quality  of  food  may  next  be  considered  in  re- 
spect to  condiments. 

Among  these  are  reckoned  salt,  vinegar,  mustard,  spices,  alcoholics, 
&c.  Salt  and  vinegar,  in  small  quantities,  without  doubt  facilitate 
digestion.  In  the  first  place,  being  palatable  ;  and  in  the  next  place, 
their  components  are  needed  by  the  system  in  the  fulfilment  of  its  duties. 
By  habit  some  become  accustomed  to  them  in  much  too  large  quantities. 

169.  Spices,  including  mustard,  in  quite  small  quantities,  give  an 
agreeable  flavor  to  the  food,  and  quicken  digestion  by  so  acting  upon  the 
nerves  of  the  stomach  as  to  rouse  the  circulation.  The  natural  exciters 
and  relishers  of  food  are,  however,  found  in  exercise  in  the  open  air,  and 
while  the  use  of  spices  in  small  quantities  may  arouse  the  stomach  to  its 
duties,  when  the  mind  has  been  absorbed  in  business,  the  ultimate  effect 


300  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

will  be  injurious,  though  not  such  as  to  make  it  worth  while  to  be  too 
particular  ;  yet  every  one  should  be  careful  not  to  acquire  the  habit  of 
using  spices  very  freely.  The  same  things  might  be  said  about  the  effects 
of  alcoholics  upon  the  stomach  ;  but  there  are  other  effects  produced  by 
whatever  contains  alcohol,  however  disguised,  that  strictly  prohibit  its 
use  under  any  name  or  in  any  quantity. 

170.  Food  may  next  be  considered  in  respect  to  its  con- 
sistence. 

Dr.  Beaumont  testifies,  that  food  must  be  of  a  certain  consistence 
before  the  digestive  process  will  begin,  and  it  is  reasonable  to  believe  it 
is  so.  Food,  to  be  sure,  is  to  pass  into  the  liquid  blood,  but  yet  it  is  it- 
self solid.  Much  liquid  in  the  stomach  would  so  dilute  the  gastric  juice, 
that  it  could  not  well  perform  its  office.  Thirst  is  an  entirely  different  sen- 
sation from  hunger.  Thirst  exists  when  fluids  are  required,  but  hunger 
when  food  is  needed.  Fluids  taken  when  there  is  no  thirst,  it  would  be 
easily  believed,  must  in  some  way  prove  injurious,  as  it  would  be  com- 
pelling the  system  to  take  care  of  that  for  which  it  had  no  use. 

171.  Dr.  Beaumont  testifies,  that  when  food  and  fluids  are  taken  to- 
gether, the  first  effort  of  the  stomach  is  to  remove  the  fluid  ;  if  the  sys- 
tem required  fluids,  which  was  signified  by  thirst,  it  was  removed  at  once, 
but  if  the  system  did  not  require  fluids,  the  removal  was  slow.  There- 
fore many  of  those  things  often  thought  the  best,  especially  in  sickness, 
cannot  be  so ;  for  instance,  gruels,  porridges,  and  the  whole  list  of  "  slops." 
If  it  be  asked  why  they  are  so  generally  allowed  by  the  physician,  the 
answer  is,  that  when  sick,  the  less  a  person  eats,  the  better,  and  there  is 
very  little  real  food  in  water  gruel,  beef  tea,  toast  coffee,  &c. ;  yet  a  patient 
will  be  content,  thinking  he  has  eaten  enough  when  he  has  taken  a  bowl 
of  such  articles.  Thus  his  mind  is  satisfied,  and  he  eats  in  fact  but  very 
little ;  and  people  understand  the  importance  of  abstinence  so  little,  they 
will  not  be  content  without  the  semblance  at  least  of  eating  something. 

172.  If  food  be  needed,  it  will  be  better,  therefore,  to  eat 
something  of  consistence,  which  will  be  well  chewed  before 
it  is  swallowed,  and  not  to  drink  in  connection  therewith,  ex- 
cept thirst  exist. 

173.  In  the  next  place,  the  quality  of  the  food  may  be 
noticed,  in  respect  to  the  time  required  for  its  digestion. 
That  which  digests  the  most  quickly,  if  it  supply  the  system 


SEC.  2.]  THE  STOMACH.  301 

with  the  same  amount  of  ingredients,  would  seem  at  least, 
under  certain  circumstances,  to  be  more  wholesome  than 
other  kinds. 

All  kinds  properly  prepared  before  taken  into  the  mouth,  and  properly 
acted  upon  there,  will  be  more  easily  digested  than  otherwise  ;  the  time 
required  for  digestion  will  also  depend  upon  the  requirement  of  the  sys- 
tem for  food  ;  as,  if  the  system  do  not  require  food,  digestion  will  not 
take  place  at  all,  and  if  more  food  be  taken  than  is  required,  even  that 
amount  which  is  required  will  not  be  quickly  digested.  It  will  also  de- 
pend upon  the  health  of  the  body. 

174.  That  some  food  should  not  require  cooking  is  not  strange,  for 
instance  eggs.  These  are  already  prepared  to  form  the  various  parts 
of  an  animal,  and  why  should  they  need  much  further  preparation  before 
the  reception  of  their  ingredients  in  the  bloodvessels  ?  Indeed,  cooking 
them  much,  changes  them  to  such  a  degree  that  they  are  quite  difficult 
of  digestion.  Raw  eggs  are  therefore  frequently  recommended  to  a  per- 
son whose  digestive  organs  are  feeble.  Cabbage  raw  digests  much  easier 
than  when  boiled ;  probably  because  its  pores  become  closed  with  the 
fatty  substance  in  which  it  is  cooked,  and  by  the  effects  of  heat.  But 
why  there  should  be  so  much  difference  in  the  time  required  for  digesting 
various  articles  of  food  strongly  resembling  each  other,  and  why  in  some 
cases  food  indigestible  in  health  should  be  quickly  digested  in  sickness, 
and  why  an  article  should  be  digested  with  difficulty  by  some  persons, 
when  generally  it  is  considered  wholesome,  cannot  be  determined. 

175.  The  following  table  from  Dr.  Beaumont,  though  not  very  instruc- 
tive, as  perhaps  there  would  be  few  persons  with  constitutions  precisely 
like  that  of  Alexis  St.  Martin,  and  consequently  few  whose  stomachs 
would  require  the  same  length  of  time  for  digesting  food — perhaps  for 
some  articles  longer,  and  for  others  shorter,  than  in  his  case  ;  yet  is 
curious,  as  showing  the  average  time  required  for  the  digesting  of  certain 
articles  by  him.  The  time  in  his  case  varied  much  in  different  experi- 
ments ;  it  depended  upon  his  health,  the  requirement  for  food,  the  quan- 
tity eaten,  the  temperature  of  the  article,  the  exhaustion  of  his  body  by 
exercise,  upon  whether  he  took  vigorous  or  gentle  exercise  or  slept  imme- 
diately after  eating  ;  and  upon  whether  he  was  in  good  humor  or  angry 
when  or  immediately  after  eating ;  and  sometimes  there  would  be  a  va- 
riation when  it  could  not  be  accounted  for. 


TABLE, 

•JCHIBITING  THE  AVERAGE  TIME  OF  DIGESTION  OF  CERTAIN  ARTICLES  OF  DIET. 


Articles. 

Prepara- 
tion. 

Time 

Articles. 

Prepara- 
tion. 

Time 

Pigs'  feet,  soused, 
Rice,      .... 
Tripe,  soused,    .     . 
Apples,  sweet, 
Trout,  salmon,  fresh 

Boiled, 
Boiled, 
Boiled, 
Raw, 
Boiled, 
Fried 

h.  m. 
I 
1 
1 
1  30 
I  30 
1  30 

Soup,  chicken,    .     . 
Pork  steak, 
Pork,  recently  salted 
Oysters,  fresh,  .     . 
Mutton,  fresh, 

Boiled, 
Broiled, 
Broiled, 
Roasted, 
Roasted, 
Baked 

h.  m. 
3 
3  15 
3  15 
3  15 
3  15 

Q     1  fi 

Venison  steak, 
Sagro,    . 

Broiled, 
Boiled, 

1  35 
1  45 

Carrot,  orange, 
Beef,  with  mustard, 

Boiled, 
Boiled 

3  15 
3  15 

Apples,  sour,  mellow 
Cabbage  &  vinegar, 
Codfish,  cured,  dry, 
Eggs,  fresh,      .     . 
Liver,  beef's,  fresh, 

Raw, 
Raw, 
Boiled, 
Raw, 
Broiled, 

2 
2 
2 
2 
9, 

Sausage,      .     .     . 
Beef,  fresh,  lean,  dry, 
Bread,  wheat,  fresh, 
Butter,       .... 
Catfish,  .... 

Broiled, 
Roasted, 
Baked, 
Melted, 
Fried 

3  15 
3  30 
3  30 
3  30 
3  30 

Milk 

Boiled 

2 

Cheese  old  strong 

Raw 

3  30 

Tapioca,     .     .     . 
Milk,    .     .     . 

Boiled, 
Raw, 

2 
2  15 

Eggs,  fresh,    .    -    i 

Boiled 
hard 

3  30 

2  18 

q   qr» 

,  domesti-    ) 
cated,                   $ 

Boiled, 

2  25 
2  30 

Flounder,  fresh,     . 
Oysters,  fresh,     .     . 

?ried, 
Stewed, 
Boiled 

3  30 
B  30 

q    on 

Potatoes,  Irish,   .     . 
Pig, 

Baked, 
Roasted, 

2  30 
9.  30 

Soup,  mutton,     .     . 
Soup,  oyster, 

Boiled, 
Boiled, 

3  30 
3  30 

Parsnips,  .... 
Meat  hashed  with  ) 
vegetables,           $ 
Lamb,  fresh,     .     . 
Goose,       .... 
Cake,  sponge, 
Cabbage  head, 
Beans,  pod,    .     . 

Boiled, 
Warm'd, 

Broiled, 
Roasted, 
Baked, 
Raw, 
Boiled, 
Fricas'd 

2  30 
2  30 

2  30 
2  30 
2  30 
2  30 
2  30 
>  45 

Turnips,  flat,      .     . 
Beef,  fresh,  lean,      ) 
with  salt  only,     \ 
3orn,  green,  &  beans, 
Beets,      .... 
Beef,  fresh,  lean, 
Ducks,  domesticated, 
fowl,  domestic, 

Boiled, 
Boiled, 

Boiled, 
Boiled, 
i^ried, 
loasted, 
Boiled, 

3  30 
3  36 

3  45 
3  45 
4 
4 
4 
4 

Custard,.     .     .     . 
Apples,  sour,  hard, 
Oysters,  fresh,     .     . 
Bass,  striped,  fresh, 
Beef,  fresh,  lean,  rare, 
steak,       .     . 
Corn  cake,     .     .     . 
Dumpling,  apple, 

Eggs,  fresh,   .     .     j 
Mutton,  fresh,  .     . 

Baked, 
Raw, 
Raw, 
Broiled, 
Roasted, 
Broiled, 
Baked, 
Boiled, 
Boiled 
soft, 
Broiled, 
Boiled 

2  45 
2  50j 
2  55 
3 
3 
3 
3 
3 
3 
3 
3 
3 

Salmon,  salted,  .     . 
Soup,   beef,  vege-  ) 
tables  &  bread,    $ 
Veal,  fresh,       .     . 
Pork,  recently  salted, 
Beef,  old  hard,  salted, 
Cabbage,     .     .     . 
Ducks,  wild, 
3uet,  mutton,   .     ., 
Veal,  fresh,    .     .     . 
Pork,  fat  and  lean, 

Boiled, 
Boiled, 

Broiled, 
^ried, 
Boiled, 
Boiled, 
loasted, 
Boiled, 
rried, 
loasted, 
Boiled 

4 
4 

4 
4  15 
4  15 
4  30 
4  30 
4  30 
4  30 
5  15 
5  30 

Pork,  recently  salted, 

Boiled, 

3 

SEC.  2.]  THE  STOMACH.  303 

176.  In  the  next  place,  the  quality  of  the  food  in  respect 
to  its  adaptation  to  satisfy  the  wants  of  the  system,  may  be 
noticed.     The  wants  of  the  system  are  fourfold.     From  in- 
fancy to  maturity  it  must  be  increased  in  size.     It  constantly 
wants  material  for  its  repairs ;    at  times  it  requires  material 
to  fatten  itself,  and  a  supply  of  food  as  fuel  is  a  want  that  is 
continuous,  but  more  urgent  at  some  times  than  at  others. 

The  character  of  the  food  should,  therefore,  differ  at  different  periods 
of  life.  To  understand  this  folly,  it  should  be.  remembered,  as  every  day's 
experience  testifies,  that  exercise  tends  to  produce  heat. 

177.  In  infancy,  therefore,  food  is  required  which  shall 
cause  the  growth  of  the  child,  and  also  produce  heat,  and 
form  fat. 

For  in  the  first  place,  the  child,  though  small,  has  a  great  extent  of 
surface  in  proportion  to  the  weight  of  its  body,  therefore  it  must  be  sup- 
plied with  a  sufficient  quantity  of  fat  to  prevent  the  rapid  passage  of 
heat  from  its  body.  Hence  why,  before  infants  are  old  enough  to  ex- 
ercise, they  are  so  fat,  and  of  course,  as  the  child  is  growing  the  fat  must 
also  grow.  There  are  additional  reasons,  hereafter  to  be  given,  for  the 
fat  so  conspicuous  in  young  children.  Too  great  a  supply  of  fat  makes 
the  child  too  heavy,  and  by  its  weight  tends  to  cause  deformity.  There 
must,  therefore,  be  a  very  accurate  adjustment  between  the  quality  and 
quantity  of  food  productive  of  fat  and  the  wants  of  the  child. 

177.  Milk  has  been  furnished  as  the  food  of  young  ani- 
mals ;  it  therefore  must  contain,  for  all  the  works  of  nature 
are  perfect,  the  ingredients  required  by  the  system  in  the 
production  of  fat. 

What  part  of  the  milk  is  chiefly  adapted  to  this  purpose  seems  to  be 
indicated  by  one  fact,  viz.,  it  is  quite  impossible  to  fatten  animals  on 
skimmed  milk,  or  buttermilk  ;  they  will,  however,  grow  well  in  other 
respects.  The  butter  which  has  been  removed,  or  something  to  take 
the  place,  is  essential  for  fattening  animals.  This  is  also  indicated  by 
the  fact,  that  the  milk  of  the  human  species  contains  more  butter  than 
the  milk  of  any  other  animals,  and  so  it  should  be  ;  as  every  other  ani- 
mal when  young,  has  more  of  external  protection  than  infants,  it,  there- 
fore, requires  more  of  the  internal  protection,  viz.,  the  fat.  When, 


304  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

therefore,  an  infant  cannot  receive  its  most  natural  food,  that  is  advised 
which  is  most  similar.*  Asses'  milk  first,  goats'  milk  next,  cows'  milk 
next.  When  this  last  is  used,  its  quality  will  be  improved  by  allowing  it 
to  stand  for  a  short  time,  not  till  any  cream  can  be  observed  on  the 
surface,  but  till  the  upper  part  of  the  milk  has  become  a  little  richer  than 
the  lower  part.  The  upper  half  or  two-thirds  may  then  be  carefully 
dipped  off  for  use. 

178.  Another  fact  would  show  that  sugar  is  well  adapted 
to  fatten  the  system. 

For  by  using  it  in  considerable  quantities,  all  kinds  of  animals,  the 
dog,  the  horse,  the  cow,  will  speedily  become  very  fat.  Children  are 
especially  fond  of  sugar  and  sweet  articles,  and  in  the  milk  of  the  hu- 
man species  sugar  is  more  abundant  than  in  case  of  any  other  animal. 
When  it  is  necessary  to  give  cows'  milk  to  an  infant,  it  is  usual  and 
proper  to  add  a  small  quantity  of  refined  sugar. 

179.  The  food  of  the  child  should  gradually  change  in 
its  character,  as  it  begins  to  take  exercise. 

This  is  what  occurs  in  the  natural  food  of  the  child.  The  appear- 
ance of  teeth,  signifies  that  there  is  need  for  their  use  upon  food  requir- 
ing to  be  chewed.  But  as  the  teeth,  upon  first  appearance,  are  not  adapt- 
ed to  chew  hard  food,  such  articles  as  bread  and  milk  are  indicated, 
while  as  the  grinding  teeth  and  wants  of  the  child  develop  themselves, 
at  the  same  time  harder  food  and  meat  diet  is  indicated.  The  appetite 
changes  in  corresponding  degrees. 

180.  Nature  has  therefore  made  the  food  she  has  designed 
a  child  to  receive,  perfect ;  and  nothing  which  man  can  con- 
trive or  prepare,  can  compare  with  it.      Whatever  comes  from 
his  hand  must  differ  more  or  less  from  the  requirements  of  the 
system. 

Producing  either  too  much  fat  or  too  little,  and  though  after  a  few 
months  the  food  of  the  infant  may  be  changed  for  the  milk  of  the  cow, 
milk,  and  milk  only,  should  be  used  as  the  most  perfect  and  wholesome 
diet,  till  the  child  has  teeth.  Till  its  teeth  are  fully  developed  and  strong, 

*  I  do  not  know  that  the  milk  of  the  swine  has  ever  been  analyzed, 
but  the  want  of  external  covering  would  signify  a  near  approach  to  the 
wants  of  the  human  species,  and  it  might  be  inferred  they  would  be 
satisfied  by  food  of  a  similar  character. 


SEC.  2.]  THE  STOMACH.  305 

it  should  have  a  diet  of  bread  and  milk,  and  afterwards  the  appetite  of 
the  child,  without  the  system  is  peculiarly  constituted,  will  generally  de- 
sire a  vegetable  diet,  puddings,  pies,  bread,  potatoes,  &c.,  rather  than 
meat,  until  maturer  years. 

181.  By  rigidly  following  such  a  course,  not  only  will  a 
parent  do  the   best  for   the   child,   but  save  herself  much 
trouble. 

As  the  child  will  not  cry  for  food  it  has  never  tasted.  If  sugar  be 
given  to  the  child  it  should  be  dissolved  in  its  food,  as  then  it  will  not 
acquire  a  taste  for  sugar,  or  know  what  it  is  when  it  sees  it.  Many 
things  would  of  themselves  do  a  child  no  harm  in  many  instances,  but 
they  must  not  for  once  be  given  to  a  child,  as  thereby  a  taste  is  aroused 
which  will  not  be  easily  satisfied.  And  as  "  ignorance  is  bliss"  to  the 
child,  "  'tis  folly"  for  it  "  to  be  wise." 

182.  In  after  life,  the  quantity  of  fat  should  depend,  and 
it  does,  on  the  exercise  of  a  person. 

For  as  exercise  produces  much  heat,  it  is  not  necessary  that  it  should 
be  husbanded  with  much  care.  Ladies  therefore,  as  a  general  thing, 
require  more  fat  than  gentlemen,  and  their  food  should  not  be  of  the 
same  kind,  and  they  are  more  apt  to  be  fond  of  vegetables,  fruit,  pastry, 
&c. 

183.  In  the  fall  and  winter,  different  requirements  exist 
from  those  of  summer. 

There  are  then  different  appetites,  and  nature  supplies  different  food 
for  man  and  animals.  To  animals,  she  supplies  an  abundance  of  starch ; 
they  find  it  in  acorns,  in  potatoes,  and  in  grains  which  ripen  in  the  fall 
of  the  year  ;  and  some  kinds  of  potatoes  are  worth  much  more  to  fatten 
animals  than  others ;  the  same  is  true  of  grains,  and  when  examined,  it 
is  found,  that  other  things  being  equal,  those  kinds  of  food  containing 
the  most  starch,  fatten  an  animal  the  most  rapidly. 

184.  Again,  those  kinds  of  food  containing  starch,  fatten  an  animal 
quicker  if  they  be  boiled  ;  and  the  reason  of  this  seems  to  be  that  starch 
is  in  the  form  of  kernels,  composed  of  concentric  layers  like  an  onion. 
The  external  layer  is  cracked  by  the  heat  of  boiling  temperature,  and 
the  juices  of  the  stomach  can  thus  act  on  the  internal  parts  of  the  starch 
kernels,  many  of  which  otherwise  escape  digestion  in  the  stomach. 

185.  These  things  would  settle,  without  a  doubt,  that  starch  is  a 


306  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

kind  of  food  useful  in  producing  fat,  and  it  has  already  been  shown  that 
sugar  and  butter  are  useful  for  a  similar  purpose.  The  nuts  eaten  by 
squirrels  and  many  other  animals,  furnish  a  supply  of  oil  with  which  the 
squirrel  makes  itself  very  fat  in  the  fall  of  the  year.  Man  is  also  in- 
clined to  eat  fatty  food  in  the  fall  and  winter,  and  fat  abounds  in  the 
meat  food  eaten  at  such  times. 

186.  It  would  seem  therefore  that  sugar,  starch,  butter, 
oils  and  fats,  must  be  very  similar  to  each  other,  and  so 
they  are.     Indeed,  they  are  composed  of  precisely  the  same 
ingredients,  viz.,  oxygen,  hydrogen,  and  carbon,  the  propor- 
tions of  the  ingredients  differing  in  the  different  articles. 

The  fat  of  the  body  can,  therefore,  be  very  easily  formed  from  any  of 
the  substances  mentioned.  Gum  is  of  a  similar  character,  so  also  is 
gelatine  or  animal  jelly.  Many  animals  eat  gum  and  grow  fat,  and  it 
is  often  recommended  by  the  physician  for  the  sick  person.  Alcohol  is 
also  composed  of  carbon,  hydrogen,  and  oxygen,  and  when  digested  in 
the  stomach,  is  capable  of  producing  fat,  as  sometimes  seen  in  beer 
drinkers,  and  in  olden  times,  in  case  of  those  who,  on  recovering  from 
sickness,  were  ordered  to  use  large  quantities  of  brandy,  &c.,  which 
did  not  cause  intoxication,  to  the  surprise  of  the  patient,  who  saw  him- 
self growing  fat,  but  not  strong.  Alcoholics  will  not  usually  be  digested, 
and  when  they  are,  it  is  worthy  of  notice  that  they  do  not  increase  the 
strength  of  a  person  in  the  slightest  degree,  but  form  a  soft  unhealthy  fat, 
not  needed,  but  injurious,  if  for  no  other  reason,  because  the  system  has 
spent  its  powers  in  preparing  it  unnecessarily. 

187.  When  the  active  duties  of  life  are  past,  and  age 
advances,  the  powers  of  the  system  being  enfeebled  and  inca- 
pable of  producing  heat  abundantly,  the  heat  produced  must 
not  be  allowed  to  pass  off. 

The  food  must,  of  course,  be  such  that  fat  can  be  formed  from  it,  and 
in  this  respect,  second  childhood  compares  with  the  first.  And  do  not 
the  appetites  change  with  declining  years?  And  does  not  the  fat  accu- 
mulate ?  Thus  every  class  of  facts  tend  to  show  that  the  food  is  of  dif- 
ferent qualities,  and  that  certain  qualities  of  food  are  adapted  to  form 
fat,  and  that  without  these  are  taken,  fat  cannot  be  formed.  Those  who 
do  not  wish  to  be  corpulent  or  fat,  are  not  under  the  necessity  of  being 
BO  :  true,  they  may  become  so  much  easier  than  others.  But  did  any  one 


SEC.  2.]  THE  STOMACH.  307 

ever  know  a  tiger  to  be  fat,  or  any  animal  to  grow  fat  when  fed  upon 
lean  meat,  or  skimmed  milk  or  buttermilk?  In  rare  cases,  and  under 
very  favorable  circumstances,  an  animal  might  become  quite  fat  by 
means  of  the  sugar  contained  in  skimmed  milk  and  buttermilk,  but  usually 
there  will  be  a  use  for  this  besides  for  forming  fat. 

188.  Active  exercise  would  seem  also  to  prevent  a  ten- 
dency to  the  formation  of  fat,  while  on  the  other  hand  indo- 
lence, eating  sugar,  gum,  starch  and  fat,  will,  with  good  health 
and  a  cheerful  disposition,  tend  in  most  constitutions  to  produce 
fat. 

189.  The  next  question  to  be  settled  is,  that  the  food 
adapted  to  produce  fat,  is  also  adapted  to  produce  he"at. 

In  proof  of  this  it  may  be  noticed,  that  bees  lay  up  a  store  of  honey 
for  use  during  the  winter.  The  use  to  which  it  is  put  is  evidently  to 
keep  them  properly  warm,  for  if  the  winter  be  very  long  or  very  cold, 
more  honey  is  used,  and  the  instant  the  honey  of  a  swarm  is  exhausted, 
it  dies.  Housing  bees  in  a  warm  place  (it  must  not  be  too  warm) 
"  saves  the  honey."  A  thermometer  placed  in  a  swarm  of  bees,  will 
show  that  it  is  warm.  As  the  bees  do  not  take  exercise  during  the 
winter,  there  cannot  be  other  use  for  the  honey  than  to  produce  heat. 
Honey  is  of  the  same  class  as  sugar. 

190.  The  fat  stored  by  the  squirrel  and  bear,  being  gradually  ex- 
hausted while  they  are  quiet  in  their  winter  quarters,  indicates  that  fats, 
oils,  &c.,  are  used  to  keep  the  body  warm. 

191.  Cows  and  other  animals  turned  out  of  doors  in  cold  weather 
will  not  become  fat,  nor  give  a  good  supply  of  milk  yielding  butter,  but 
grow  lean  ;  which  shows  that  starchy  and  gummy  food,  which  under 
some  circumstances  would  be  used  to  fatten  and  form  butter,  are  neces- 
sary, and  used  to  keep  the  animal  warm. 

192.  Again,  those  very  periods  of  life  which  require 
that  the  system  should  be  protected  from  the  loss  of  heat,  are 
those  periods  when  heat,  to  as  great  a  degree  as  possible, 
should  be  produced. 

Therefore,  there  should  be  a  demand  at  such  periods  for  food  adapted 
to  warm  the  system.  But  it  has  been  seen  that  there  is  a  special  de- 
mand at  such  periods  only  for  food  adapted  to  fatten  the  system  ;  from 


308  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

which  it  would  follow,  that  the  food  to  warm  and  the  food  to  fatten  were 
the  same.* 

193.  In   summer  there  is  comparatively  little  need  of 
food  to  warm  the  system,  and  no  need  of  food  to  fatten  the 
system.     Only  a  small  quantity  of  the  kinds  of  food  above 
indicated  should  then  be  eaten. 

Fevers  which  prevail  in  summer,  are  mostly  found  among  those  who 
by  hard  labor  produce  a  hearty  appetite,  to  satisfy  which  they  eat  a 
large  quantity  of  food  ill  adapted  to  the  purpose.  They  require  a  large 
quantity  of  food,  but  of  a  proper  quality.  Farmers  have  learned  by  ex- 
perience, that  buttermilk  and  skimmed  milk  are  better  adapted  to  their 
wants  in  haying  and  harvest  time,  than  new  milk,  containing  of  course 
an  amount  of  butter. 

194.  A  person  sick  in  a  warm  room,  in  summer  or  win- 
ter, of  course  would  require  but  little  heat-producing  food. 

For  there  is  little  need  that  heat  be  produced,  and  there  is  a  stock  or 
store  of  fat  which  has  been  prepared  for  use,  and  which  may  be  used 
with  little  effort  on  the  part  of  the  system. 

195.  In  the  fall  there  is  requirement  for   an  increased 
quantity  of  food,  both  to  fatten  the  system  and  keep  it  warm. 

As  the  fat  is  deposited  somewhat  in  proportion  to  the  exposure  of  the 
system,  it  will  not  be  best  to  put  on  winter  clothing  too  early  in  the 
year  ;  for  as  the  coat  of  a  horse  "  thickens  up  "  when  his  blanket  is  left 
off  till  late,  so  will  the  fat  be  increased  as  an  internal  coat. 

196.  Attention  may  now  be  given  to  the  qualities  of  the 
-food,  adapting  it  to  answer  the  wants  of  the  system  in  respect 
to  its  growth  and  repair. 

It  must  be  evident,  that  food  adapted  to  promote  the  growth  of  the 
body,  must  be  adapted  to  its  repair.  There  are,  however,  several  things 
to  be  considered.  It  is  not  certain  how  frequently  some  parts  undergo  a 
change — it  cannot  be  very,  frequently — and  therefore,  once  formed,  I  ut 

*  The  question  may  arise — Are  the  sugar,  starch,  gum,  &c.,  changed 
into  fat  by  the  digestive  action  of  the  stomach,  or  can  the  system  make 
use  of  sugar  to  produce  heat?  Of  course  they  are  changed  into  fat 
when  they  are  used  to  fatten  the  system,  and  they  probably  are  when 
used  for  the  purpose  of  warming  the  body ;  but  the  matter  is  unknown. 


SEC.  2.]  THE  STOMACH.  309 

little  food  would  be  required  on  their  account ;  while  growing,  their  de- 
mands would  be  greater. 

197.  Some  of  the  simple  elements  exist  in  the  body  in  very  small 
quantity,  but  yet  they  are  requisite,  and  must  be  eaten— in  how  large 
quantities  and  how  frequently,  will  depend  upon  whether  they  assist  to 
form  a  part  of  the  body  which  changes  frequently  or  unfrequently ;  and 
whether  substance  which  has  formed  one  part  of  the  body,  can  afterwards 
assist  in  forming  another  part. 

198.  The  constituents  of  the  body  being  so  numerous, 
and   undergoing   a  change   more   or   less  frequently,   may 
account  for  an  important  fact,  viz.,  that  it  is  necessary  for 
man  and  animals  to  eat  a  variety  of  articles. 

Some  may  be  the  chief  and  most  important  ones,  but  others  must  be 
taken  more  or  less  frequently  ;  dogs  fed  for  some  weeks  on  one  kind  of 
food,  pine  away  and  die — and  one  German  physician  fell  a  victim  to  the 
cause  of  science,  by  trying  the  experiment  of  living  upon  one  kind  of 
food  for  a  long  time. 

199.  It  is  a  difficult  thing  to  point  out  all  those  articles 
which  are  profitable  or  necessary  to  nourish  the  body. 

But  as  animals  grow  when  fed  on  skimmed  or  buttermilk  ;  and  as  the 
young  chick  is  formed  from  the  egg,  and  as  the  tiger  living  upon  lean 
meat  is  strong,  and  as  fish  fed  upon  lean  meat  grow  very  fast,  but  are 
lean — it  may  be  inferred  that  milk,  eggs,  and  the  lean  meat  of  beasts, 
birds,  or  fishes  is  well  adapted  to  strengthen  the  body  and  to  cause  it  to 
grow  ;  but  it  is  also  seen  that  certain  animals  living  upon  fruits,  and 
other  animals  living  upon  grasses,  grains,  or  roots,  are  also  strong  and 
grow  rapidly  when  young.  Upon  farther  examination  it  has  Feen 
found,  that  the  same  kinds  of  compound  elements  exist  in  these  articles 
of  food  as  are  found  in  meat,  eggs,  or  milk.  In  some  of  the  grains  they 
exist  more  abundantly  than  in  others.  The  same  is  true  of  the  grasses 
or  other  articles  of  food  used  as  nourishment  by  animals. 

200.  In  every  organ  and  every  part  of  any  organ  of  the 
body,  more  or  less  nitrogen  will  be  found.     Whatever,  there- 
fore,  is  used  for  tbe  purpose  of  forming  any  part  of  the  body, 
must  contain  nitrogen.* 

*  Some,  however,  have  contended  that  nitrogen  could  be,  and  was, 
obtained  from  the  air.  Of  this,  however,  there  is  at  present  no  proof. 


310  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

Some  have  therefore  laid  it  down  as  a  rule  that  the  more  nitrogen  any 
article  of  food  contains,  the  more  nourishing  would  it  be  ;  and  upon  this 
principle,  tables  have  been  formed  showing  the  comparative  qualities  of 
different  kinds  of  food,  but  they  have  not  been  found  very  satisfactory. 

201.  If  we  subtract  fat,  sugar,  starch,  and  gum  from  the 
articles  usually  set  upon  the  table,  the  remainder  will  consist 
mostly,  or  entirely,  of  nourishment  and  waste  food,  the  amount 
of  which  last  will  depend  upon  the  quality  of  food  and  the 
thoroughness  of  digestion.  Of  the  amount  of  it  each  person 
must  judge  for  himself,  after  considering  the  duties  of  the 
second  stomach. 

202.  In  infancy,  when  the  child  is  growing,  and  when,  a  little  older, 
it  begins  to  exercise,  milk  is  kindly  provided  for  the  wants  of  the  child, 
in  respect  to  nourishment.  Why,  then,  should  such  food  as  arrow-root, 
or  any  of  that  class  of  food  designated  by  the  name  of  pap,  be  used  ; 
since,  not  containing  a  sufficient  amount  of  nourishment,  the  bones  of  the 
child  cannot  become  strong,  the  ligaments  cannot  fulfil  their  duties,  and 
deformities  will  be  produced,  as  well  as  bad  teeth,  and  other  evils  too 
numerous  to  mention,  all  of  which  might  be  avoided  by  the  use  of  nature's 
diet? 

203.  Because  milk  is  so  perfectly  adapted  for  infancy, 
it  would  not  be  probable  that  it  would  be  the  best  diet,  if 
used  exclusively  in  youth,  or  even  childhood,  much  less  in 
manhood. 

The  active  exercise  of  the  system  calls  for  different  food,  and  it  must 
be  taken  freely  ;  while  on  the  other  hand,  in  old  age  the  infirmities  of  the 
system  render  it  impossible  to  take  exercise,  and  nourishment  is  required 
in  only  very  small  quantities. 

204.  The  food  supplied  to  man  in  warm  climates,  the 
effect  of  heat  upon  his  feelings,  and  the  exhaustion  of  the 
system  produced  by  heat,  all  signify  that  exercise  should 
not  be  laborious  in  hot  weather,  or  in  warm  climates. 

Of  course,  if  but  little  exercise  be  taken,  the  quantity  of  nourishing 
food  should  correspond.  On  the  other  hand,  in  winter,  and  in  cold 
climates,  the  food  supplied  for  man,  the  energy  of  his  feelings,  and  the 
active  state  of  the  digestive  organs,  signify  that  man  should  take  vigorous 


SEC.  2.]  THE  STOMACH.  811 

exercise,  which  is  also  of  advantage  in  assisting  to  keep  him  warm,  and 
of  course,  he  should  then  take  an  abundance  of  nourishing  food,  to  which 
he  will  be  induced  by  his  appetite. 

205.  In  warm  weather,  therefore,  very  little  food  should 
be  used,  either  to  nourish,  warm,  or  fatten  the  system,  and 
the  same  is  true  in  cold  weather,  if  a  person  be  not  exposed 
to  cold ;  for  instance,  if  he  be  a  sedentary  person,  or  an  inva- 
lid ;  while  in  cold  weather  a  plenty  of  food  is  required  by  an 
exposed  person,  to  nourish,  to  fatten,  and  to  warm  the  body. 

206.  In  the  fifth  place,  we  may  consider  the  effects  of 
habit  upon  the  digestive  organs. 

This  is  very  great.  A  tendency  to  what  is  called  periodicity,  is  one 
of  the  most  noticeable  things  in  the  system.  Diseases  of  many  kinds 
grow  worse  and  better  at  stated  intervals,  and  many  things  which  take 
place  in  a  healthy  state  of  the  system  occur  once  in  a  certain  time,  and 
the  longer  the  time  during  which  this  has  been,  the  more  certain  is  the 
occurrence  at  the  given  time.  A  person  who  is  in  the  habit  of  waking 
at  a  certain  hour  never  fails  of  the  time.  If  food  be  taken  at  regular  in- 
tervals, the  stomach  in  a  short  time  becomes  habituated,  and  is  prepared  at 
the  time  of  eating,  to  digest  food  if  it  be  at  all  required. 

207.  It  is  very  important  that  it  be  so,  and  the  habit 
which  some  persons  have  of  changing  the  hour  of  their  meals 
on  one  or  two  days  of  the  week,  is  very  bad.     Much  better 
is  it  to  go  without  a  repast  and  eat  more  heartily  at  the  next, 
prepared  at  the  usual  hour. 

208.  In  the  sixth  place,  we  may  consider  at  what  times 
food  should  be  eaten.     Upon  this  point  much  has  been  said, 
and  it  need  not  be  repeated.     But  it  may  be  further  remark- 
ed, that  food  should  be  taken  at  a  short  time  after  rising  in 
the  morning,  a  little  while  being  allowed  for  exercise.     The 
time  of  the  next  repast  will  depend  upon  the  labor  the  per- 
son performs.     Three  times  per  day  is  as  often  as  it  is  well 
for  any  person  to  eat.     A  professional,  or  a  sedentary  person, 
will  usually  be  better  with  two  repasts.^ 

209.  If  three  repasts  are  taken,  the  second  should  be 


312  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

eaten  about  the  middle  of  the  day,  and  the  last  at  five  or  six  in 
the  afternoon. 

A  lunch  should  not  be  taken,  as  it  will  require  from  two  to  four  hours 
for  an  ordinary  repast  to  digest,  after  which  a  few  hours'  rest  is  required 
by  the  stomach.  If  a  lunch  be  taken  about  11,  in  the  midst  of  its  di- 
gestion dinner  is  eaten,  and  it  prevents  the  digestion  of  the  lunch,  which 
also  prevents  the  digestion  of  the  dinner. 

210.  If  two  repasts  be  taken,  dinner  should  be  taken 
about  three  or  four  o'clock  in  the  day,  and  without  being 
preceded  by  a  lunch. 

It  seems  better  thus,  because  then  a  heartier  repast  will  be  eaten, 
and  the  stomach  more  filled ;  and  when  the  stomach  is  quite  well  filled, 
its  muscles  can  operate  on  its  contents  to  better  advantage.  It  is  not 
well,  therefore,  to  eat  little  and  eat  often. 

211.  It  is  usually  thought  that  infants  should  eat  oftener  than  mature 
persons,  and  there  does  not  seem  to  be  any  objection  to  this  opinion,  if 
it  be  not  carried  to  the  extreme.  An  infant  does  not  take  much  Exer- 
cise, and  is  thoughtless,  and  if  it  be  not  sick,  or  fretted  by  being  made 
uncomfortable,  its  system  has  nothing  upon  which  to  bestow  its  powers, 
except  its  own  nourishment.  It  may  therefore,  without  difficulty,  be  en- 
gaged in  digesting  food  much  of  the  time.  But  the  stomach  should  have 
time  to  rest.  When  quite  young,  therefore,  to  eat  five  times  per  day 
would  seem  to  be  enough,  and  four  times  would  perhaps  be  better.  After 
a  child  has  a  little  age  it  should  eat  but  four  times  per  day. 

212.  Whether  it  eat  oftener  or  less  frequently,  it  should 
eat  at  certain  times  and  at  regular  intervals,  and  it  will  be 
of  universal  application,  that  the  youngest  child  should  not 
eat  during  the  night,  which  should  be  spent  by  it  in  sound 
sleep. 

A  little  trouble  and  time  will  be  required  to  form  good  habits  in  the 
child,  but  they  well  repay  the  care. 

213.  Drink.     Before  considering   the  changes  the  food 
undergoes  in  the  stomach,  it  may  be  well  to  treat  upon  drink. 
The  use  which  water  is  to  fulfil  in  the  body,  does  not  require 
that  it  undergo  any  change. 

It  is  received  into  the  stomach,  therefore,  merely  as  into  a  conven- 


SEC.  2.]  THE  STOMACH. 

lent  place  from  which  it  may  quickly  pass  into  the  bloodvessels  if 
needed. 

214.  Its  need  is  signified  by  the  sensation  of  thirst. 

This  does  not  ever  seem  to  be  wanting  when  drink  is  required  ;  it 
may  be  however.  It  frequently  exists  when  there  is  no  need  for  drink, 
for  this  may  be  swallowed  hastily,  and  the  stomach  filled  with  water 
without  quenching  thirst.  If,  howevei,  the  mouth  and  throat  be  rinsed 
with  water  by  a  person  who  is  very  thirsty,  and  then  water  drank 
slowly,  the  thirst  will  be  satisfied  when  a  proper  quantity  of  drink  has 
been  taken. 

215.  The  bad  effects  of  drinking  too  much  are  manifold.  Dr.  Beau- 
mont testifies  that  when  drink  is  required,  it  will  immediately  vanish 
from  the  stomach,  passing  into  the  bloodvessels  of  that  organ,  and 
thence  into  all  parts  of  the  body.  He  also  testifies  that  if  too  much 
drink  be  taken,  it  will  remain  in  the  stomach,  preventing  the  digestion 
of  the  food.  Farmers  in  summer  frequently  complain  of  being  what  they 
call  "  water-logged,"  and  say  that  they  can  feel  the  accumulated  water 
move  in  their  stomachs.  The  veins  of  such  persons  appear,  and  are,  full. 

216.  As  the  drink  passes  into  the  bloodvessels  till  they 
become  filled,    when   an  additional   quantity   will  only   be 
productive  of  harm,  thirst  should  not  be  gratified  if  it  exist 
when  the  bloodvessels  appear  full. 

The  sensation  of  thirst  is  then  produced  by  some  unhealthy  slate  of 
some  part  or  parts  of  the  nervous  system. 

217.  If  the  bloodvessels  do  not  appear  full  and  thirst  ex- 
ist, it  should  always  be  satisfied,  in  sickness  or  in  health. 

Water  requiring  no  change,  its  use  will  not  cause  any  exhaustion  of 
the  powers  of  the  body.  It  may  be  taken  at  or  between  repasts,  for  if 
needed,  it  is  at  once  removed  from  the  stomach,  and  does  not  retard  di- 
gestion ;  but  if  it  be  taken  to  "  wash  down  the  food,"  or  because  the 
beverage,  tea,  coffee,  &c.,  is  relished,  it  proves  very  harmful,  in  a  short 
time  entirely  deranging  the  powers  of  the  system. 

218.  The  temperature  of  drinks  should   be  the  same  as 
the  temperature  of  food. 

A  very  important  inference  may  be  drawn  from  what  has  just  been 
said,  viz.,  that  taking  drinks  when  a  person  is  necessarily  exposed  to 
any  contagious  cause  of  disease,  is  desirable.  For  if  the  bloodvessels 

14 


314  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

ie  filled  with  drink  frem  the  stomach,  they  cannot  so  readily  receive 
any  thing  through  other  parts  of  the  body.  Upon  going  into  a  sick 
chamber  when  there  is  any  danger,  or  before  going  out  in  the  morning  in 
a  section  of  country  where  there  is  any  cause  of  disease  suspected  in  the 
air,  it  will  be  proper  to  drink  such  a  quantity  of  fluid  as  will  fill  the 
vessels,  which  during  the  night  have  lost  a  part  of  their  contents.  If  a 
person  have  been  bitten  or  acted  upon  by  any  poison,  drinking  freely  of 
water  may  fill  the  vessels  and  prevent  the  poison  from  passing  into  the 
bloodvessels  as  it  otherwise  would. 

219.  It  will  also  be  inferred,  that  the  quantity  of  drink  a  person  can 
swallow  is  not  a  measure  of  the  capacity  of  the  stomach,  and  that  a 
person  could  drink  much  more  at  one  time  than  at  another. 

220.  Most  fluids  are  composed  for  the  most  part  of  water ; 
some  of  the  other  ingredients  of  fluids  are  digested,  and  some 
pass  through  the  stomach  into  the  second  stomach,  and  some 
pass  into  the  bloodvessels  without  undergoing  any  change. 

221.  If  fluids  be  used,  but  not  in  large  quantities,  when 
not  required,  they  will  remain  in  the  stomach  till  the  blood- 
vessels  can  receive  them.  If  they  be  used  still  more  freely, 
they  will  be  allowed  to  pass  on  into  the  second  stomach,  and 
produce  the  apparent  effect  of  a  cathartic.  If  they  be  used 
in  so  large  quantities  as  to  fill  the  stomach,  they  will  cause 
vomiting. 

A  free  use  of  fluids,  therefore,  tends  to  keep  the  bowels  open,  but  at 
the  expense  of  healthy  digestion.  As  an  emetic,  there  is  nothing,  per- 
haps, which  can  be  so  highly  recommended  as  simple  water,  if  the  object 
be  merely  to  evacuate  the  stomach.  It  should  be  drank  hastily  and  till 
vomiting  occur.  One  pint  may  be  sufficient,  or  it  may  require  three 
quarts,  but  except  a  person  be  poisoned  it  is  judged  to  be  sure  in  case  of 
every  person,  and  in  most  cases  of  poisoning.  It  acts  more  easily  than 
any  thing  else,  not  being  apt  to  cause  retching,  and  is  not  unpleasant  to 
take.  If  the  water  be  warm  it  acts  more  quickly,  and  its  action  takes 
place  more  speedily  if  the  throat  be  acted  upon  by  a  feather  or  the  finger. 
Warm  water  is  more  apt  to  make  a  person  feel  sick,  but  the  water 
should  not  be  quite  cold,  as  such  a  quantity  of  cold  substance  would  be 
likely  to  produce  a  chill. 

222.  It  should  also  be  remembered,  that  when  a  physi- 


SEC.  2.]  THE  STOMACH.  315 

cian  gives  an  emetic,  he  has  frequently  other  objects  in  view 
besides  emptying  the  stomach.  Water,  perhaps,  would  not 
then  be  the  best  thing. 

223.  Water  used  in  large  quantities  also  tends  to  increase 
the  action  of  all  those  organs  by  which  watery  substance  is 
passed  from  the  system. 

For  as  the  bloodvessels  become  too  full  for  their  good,  nature  en- 
den  vors  to  lessen  their  contents  by  causing  the  skin  to  perspire,  the 
lungs  to  pass  off  more  moisture,  &c.  Hence  a  person  who  wishes  to 
sweat,  drinks  freely  to  assist. 

224.  From  what  has  been  said,  it  will  be  seen  that  the 
first  effort  made  in  the  stomach  will  have  for  its  aim  to  re- 
move the  superabundant  fluid.      The  first   process  in  the 
digestion  of  milk,  for  example,  is  the  curdling  of  it;  the 
second  is  the  removal  of  the  whey,  or  the  watery  portion, 
more  strictly  speaking. 

When  curdled  milk  is  "  thrown  up,"  therefore,  it  signifies  not  that 
the  digestion  is  unhealthy,  but  that  too  much  food  has  been  taken.* 

225.  After  food  has  been  reduced  to  about  the  consistence 
of  a  paste,  it  is  mixed  with  the  gastric  juice,  and  begins  to 
change  to  a  grayish  color ;  little  by  little  it  becomes  of  a 
uniform  consistence,  like  that  of  soft  paste,  is  called  chyme, 
and  passes  on  into  the  second  stomach. 

226.  Certain  substances,  either  from  their  nature  or  their  quantity, 
cannot  undergo  this  change  ;  but  they  must  not  be  allowed  to  remain  in 
the  stomach,  as  the  room  will  be  required  for  wholesome  food.     Some- 
times they  are  removed  by  the  passage  into  the  second  stomach  ;  some- 
times they  are  sent  back  through  the  oesophagus.     Each  operation  takes 
place  under  the  influence  of  the  nervous  system,  and  of  course,  the  per- 
fection with  which  it  takes  place,  depends  upon  the  health  of  the  nervous 
system. 

227.  This  is  especially  worthy  of  notice  in  respect  to  the  action  of 
certain  poisons  which  ought  to  be  evacuated  from  the  stomach,  but 

*  Many  a  child  has  doubtless  received  medicine  to  prevent  milk 
from  curdling  and  "  becoming  so  hard  "  upon  its  stomach. 


316  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

which  are  not ;  for  instance,  if  a  person  have  taken  opium,  laudanum,  or 
any  thing  which  stupefies,  he  not  only  is  loo  insensible  to  swallow  an 
emetic,  but  it  would  not  usually  operate  if  he  did.  Cold  applications 
are  first  to  be  made  to  his  head,  and  warm  applications  to  his  feet,  and 
rubbing  tried  till  his  senses  recover  a  little,  when  medicine  may  operate. 

228.  It  may  be  useful  to  notice,  in  this  connection,  that 
common  mustard  will  be  a  very  active  emetic. 

It  can  be  readily  had  in  almost  any  case  of  poisoning ;  where  it 
cannot,  water  should  be  drank  as  before  mentioned.  The  mustard  sold 
at  the  shops  is  too  often  impure.  If  unground  it  should  be  bruised  before 
it  is  taken,  and  used  in  any  way  most  desirable  for  the  person  to  swallow 
it  in  the  quantity  of  a  table-spoonful,  if  so  much  be  necessary.  There 
will  be  no  danger  of  taking  too  much,  but  there  may  be  of  taking  too  little. 

229.  If  any  acid,  ley,  or  the  like,  have  been  swallowed,  cold  water 
should  be  taken  as  quickly  as  possible,  and  in  large  quantities.  If  any 
poisonous  substance,  not  a  liquid,  have  been  taken,  some  kind  of  thin 
paste,  as  of  flour  and  water,  or  the  like,  should  be  used  before  the 
emetic.  The  object  is  to  cause  the  poison  to  be  taken  off  from  the  sides 
of  the  stomach  by  the  paste.  In  such  cases,  also,  a  series  of  emetics 
preceded  by  gruel-like  paste  should  be  used,  that  there  may  be  a  certainty 
that  the  poison  has  been  entirely  evacuated. 

230.  There  are  three  things  to  be  kept  in  mind  therefore, 
if  a  person  be  poisoned.  1st.  To  prevent  the  poison  from 
acting  on  the  stomach,  either  by  diluting  it  as  in  case  of 
acids,  &c.,  by  drinking  largely  of  water,  or  by  altering  it, 
as  when  eggs  are  used  to  change  corrosive  sublimate  (the 
most  common  of  bed-bug  poisons).  2d.  To  remove  it  from 
the  stomach  by  vomiting,  or  if  a  person  continue  stupid,  by 
a  stomach  pump.  3d.  To  counteract  the  effects  of  the  poison, 
which  are  in  the  first  place  stupor,  which  a  person  may 
combat  by  cold  applications  to  the  head,  warmth  to  the  feet, 
exercise,  such  as  walking  the  person  about,  and  rubbing ; 
in  the  second  place  inflammation,  which  will  require  atten- 
tion for  a  long  time  in  many  cases,  and  is,  if  curable,  of  such 
nature,  that  delay  till  a  physician  can  be  called  will  not  be 
hazardous,  as  it  will  be  if  a  person  have  become  insensible. 


SEC.  3.]  SECOND  STOMACH,  LIVER,  ETC.  817 

SECTION  3. — The  Second  Stomachy  Liver,  Pancreas,  Spleen, 
Colon,  SfC. 

231.  The  second  stomach  is  a  long  tube,  like  the  stomach 
composed  of  a  muscular  coat,  an  external  covering  called 
the  peritoneal  coat,  and  a  lining  called  the  villous,  but  usu- 
ally the  mucous  coat  or  membrane.  Between  the  muscu- 
lar, and  outer  and  inner  coats  of  the  stomach,  are  thin  layers 
of  cellular  substance. 

232.  A  common  name  for  the  second  stomach  is  the  small  intestines, 
and  the  tube  is  divided  into  three  parts,  the  first,  upper  or  nearest  to  the 
stomach  portion,  from  9  to  12  inches  in  length,  is  called  the  duodenum. 
It  is  a  little  larger  than  the  other  parts,  which  equally  divide  the  re- 
mainder of  the  tube  ;  the  first  of  these  is  called  the  jejunum,  from  being 
usually  empty,  the  remaining,  or  lowest,  or  last  half,  is  called  the  ileum. 

233.  The  whole  length  of  the  canal  may,  however,  be  considered  as 
one  organ.     It  is  situated  in  the  abdomen,  and  is  subject  to  the  same 
effects  of  pressure  as  the  stomach,  and  it  is  modified  precisely  as  in  case 
of  the  stomach. 

234.  The  second  stomach  commences  at  the  pylorus,  and 
passing  upward  and  backward  a  very  short  distance,  it  turns 
downward,  but  almost  immediately  bends  again,  and  passes  al- 
most to  the  left  side  of  the  body  (Fig.  95).     It  then  comes  a 
little  forward,  and  is  found  just  within  the  muscles  of  the 
sides  of  the  abdomen,  where  it  begins  to  pass  up  and  down, 
and  also  to  find  its  way  to  the  right  side,  as  seen  in  Lith. 
PL  3,  Fig.  1 ;  it  then  takes  a  back  course  to  the  left  side,  to 
again  come  back  and  terminate  in  the  colon,  which  commences 
in  the  right  and  bottom  part  of  the  abdomen  (PI.  3,  Fig.  1). 

235.  The  upper,  straight,  or  duodenal  part  of  the  second 
stomach,  is  somewhat  closely  confined  to  a  single  position, 
but  the  remaining  portions  are  retained  in  their  positions  by 
a  wide  ribbon-like  appendage,  called  the  mesentery,  which 
allows  of  great  extent  of  motion  in  any  direction  (Fig.  9(5). 


819 


THE  DIGESTIVE  ORGANS. 
Fig.  95. 


f CHAP.  I. 


Fig.  95. — 1,  Liver  turned  up  and  laid  back.  2,  Fissure  in  the  under  surface  of  lha 
liver.  3,  Gall  bladder.  4,  Stomach.  5,  Lower  portion  of  oesophagus.  6,  Pyloru3. 
7,  Head  of  pancreas.  22,  Small  extremity  of  pancreas.  10,  Spleen.  13  to  24^  Blood- 
vessels.  A,  Opening  of  the  ducts  from  the  pancreas,  liver,  and  gall  bladder.  B,  Du- 
odenum open,  that  the  folds  of  its  internal  surface  may  be  seen. 

236.  The  structure,  as  observed,  is  similar  to  that  of  the 
stomach,  the  external  coat  is  a  part  of  the  same  as  on  the 
stomach  (Fig.  96).     The  muscular  coat  is  composed  of  two 
layers  ;  one  consists  of  circular  fibres,  more  or  less  near  to 
each  other,  as  the  case  may  be ;  the  other  consists  of  fibies, 
which  extending  r'n  the  direction  of  the  length  of  the  intestine, 
shorten  it  when  they  contract ;  the  circular  fibres,  by  con- 
traction, lessen  its  diameter  or  close  it. 

237.  The  mucous  coat  is  much  like  that  of  the  stomach, 
but  is  arranged  in  the  form  of  little  folds  (Fig.  95),  or  plaits, 
by  which  a  greater  extent  of  surface  is  gained.     It  contains 
many  follicles,  cryptae,  or  simple  glands,  from  the  tiny  mouths 
of  which  a  constant  flow  of  substance  takes  place  to  lubri- 
cate the  canal. 


SEP.  3.] 


SECOND  STOMACH,  LIVER,  ETC. 


Fig.  96. 


Fig.  96.— Represents  a  section  of  the  middle  portion  of  the  abdomen.  The  organi 
are  somewhat  displaced  and  disproportioned,  the  chief  object  being  to  exhibit  the  peri- 
toneal coat,  Commencing  at  1,  it  can  be  traced  up  under  and  lining  D,  the  diaphragm 
from  which  it  is  "  reflected"  at  3,  to  the  liver  L,  over  the  front  edee  of  which  it  can  be 
followed,  and  under  the  liver  to  4,  where  it  turns  on  to  the  stomach,  and  at  5,  passes 
down  in  front  of  the  abdominal  organs  to  a  greater  or  less  distance,  when  it  turns  up- 
ward, forming  a  kind  of  apron,  commonly  called  the  caul,  a  beautiful  thin  membrane 
in  appearance,  netted  over  with  fat,  being  the  part  butchers  put  upon  the  front  quarters 
of  veal  to  give  a  better  appearance,  as  the  fat  caul  from  a  good  animal  can  be  made  to 
improve  the  appearance  of  an  indifferent  one.  It  can  be  traced  to  the  colon  C,  one  part 
of  which  it  covers,  and  then  leaves  it  to  go  to  the  back-bone,  touching  upon  and 
partly  covering  the  duodenum  D,  when  again  it  comes  away  lor  some  distance  to  form 
the  outer  coatof  the  small  intestine ;  the  general  outline  of  its  convolutions  being  shown 
by  I.  The -peritoneal  coat  can  then  be  ft.  Mowed  back  to  the  the  spinal  column,  the  two 
layers  adhering  at  10,  formin?  the  ribbon-like  part,  called  the  mesentery,  between  the 
two  thicknesses  of  which  the  bloodvessels,  the  nerves,  the  lacteals,  and  the  glands  of  the 
intestine  are  found.  After  continuing  in  a  similar  manner  about  the  entire  length  of 
the  second  stomach,  it  follows  down  to  11,  turns  over  the  vessicle  B,  and  pa^as 
up  from  12  to  1,  lining  the  walls  of  the  abdomen,  being  there  commonly  called  the 
film.  The  peritoneal  coat  or  peritoneum  adheres  or  grows  to,  or  rather  is  a  part  of 
those  organs  apon  which  it- is  found  ;  the  surface  opposite  to  that  which  adheres,  being 
"  free,"  viz.,  not  adherent  to  any  thing,  but  continually  moistened  with  a  very  glairy 
fluid.  In  general  appearance,  the  peritoneum  is  a  light  pearl-colored,  dense,  strong 
membrane,  rather  easily  torn  off  from  the  parts  to  which  it  belongs.  If  attention  bs 


320  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

To  keep  the  muscles  in  action,  and  to  supply  this  substance,  the 
second  stomach  must  be  furnished  plentifully  with  bloodvessels ;  and  must 
receive  nervous  influence,  and  be  acted  upon,  indirectly  at  least,  by  the 
mind. 

238.  Firm  substances,  like  small  lumps  or  kernels,  and  called  glands, 
are  found  in  the  sides  of  the  second  stomach.  Their  use  or  intimate 
structure  has  not  yet  been  ascertained,  and  they  are  not  probably  rightly 
called. 

239.  The  diameter  of  the  second  stomach  varies  in  its  dif- 
ferent parts,  and  very  much  in  different  individuals.  Its  length 
is  more  variable  than  its  diameter,  especially  in  different 
species  of  animals. 

In  the  animals  which  feed  upon  grasses  and  food  containing  much 
waste  substance,  the  second  stomach  is  very  long — in  the  sheep,  from 
twenty-five  to  thirty-five  times  the  length  of  its  body.  In  animals  like  the 
tiger,  living  upon  a  meat  diet,  it  is  short — in  his  case  being  only  three 
times  the  length  of  his  body.  In  man,  it  is  intermediate — sometimes  as 
short  as  five  feet,  but  usually  from  sixteen  to  twenty-five  feet ;  though 
sometimes  as  long  as  thirty-one  feet. 

240.  In  animals  which  change  the  character  of  their  food  and  their 
habits  at  certain  stages  of  their  existence  ;  as,  for  instance,  in  some  of  the 
frog  species,  the  length  of  the  second  stomach  varies  accordingly — in  the  . 
tadpole  being  very  long,  signifying  that  the  animal  lives  upon  vegetable 

again  bestowed  upon  the  figure,  what  appears  another  membrane,  will  be  seen  at  2, 
which  passing  down  covers  one  part  of  the  stomach,  adhering  at  4,  to  the  peritoneum 
previously  traced,  and  also  at  5,  from  which  it  follows  down,  forming  part  of  the  caul, 
the  two  layers  adhering  to  each  other.  It  can  then  be  traced  up  to  the  transverse  colon ; 
the  surfaces  between  which  6  is  placed,  not  adhering,  but  are  moistened  by  serous 
fluid.  It  forms  the  outer  coat  of  the  upper  part  of  the  colon,  adhering  to  its  companion 
between  the  colon  and  D,  the  upper  part  of  which  it  covers  when  passing  over  the 
pancreas,  it  is  found  at  2  again.  [Thus  all  the  organs  of  the  abdomen  may  move  upon 
each  other  without  the  slightest  degree  of  friction.  The  reader  must  not  gain  an  idea 
that  there  are  any  spaces  between  the  organs.  They  are  in  close  contact,  unless 
separated  by  collections  of  water  in  case  of  dropsy,  which,  from  the  great  extent  of 
surface,  may  be  very  great  in  quantity  in  a  short  time.  Just  beneath  the  free  surface 
of  the  peritoneum  a  beautiful  network  of  bloodvessels  is  found,  the  number  of  which 
is  almost  infinite,  whence  inflammation  of  the  peritoneum  is  apt  to  be  very  serious, 
and  must  not  be  trifled  with.  The  healthful  fulfilment  of  its  duties  requires  also  the 
action  of  nervous  influence,  and  as  the  action  of  the  nervous  influence  as  well  as  the 
structure  should  be  and  is  similar  in  the  whole  extent  of  the  peritoneum,  disease  of  any 
part  very  quickly  extends  under  the  slightest  aggravation.  Though  slightly  irresu- 
far,  attention  may  here  be  drawn,  as  the  cut  will  enforce  the  idea,  to  the  fact  that 
the  organs  of  the  abdomen  are  composed  of  many  different  parts|  differently  con- 
structed, and  requiring  nervous  influence  differing  in  its  effects  and  degree ;  hence 
subject  to  different  diseases  and  by  a  variety  of  causes,  all  which  things  exhibit,  in 
a  striking  light,  the  danger  of  tampering  with  the  laws  of  health,  and  the  importance 
of  the  greatest  discretion,  learning,  and  experience  on  the  pan  of  an  adviser  when 
disease  exists.] 


EEC.  3.]  SECOND  STOMACH,  LIVER,  ETC.  321 

diet,  seeds,  roots,  &c. ;  while  in  the  full-grown  frog  it  is  comparatively 
short,  as  he  supports  his  life  by  using  meat  diet,  bugs,  worms,  &c. 

241.  In  the  human  species  it  will  probably  be  found  almost  universal, 
that  those  persons  who  are  fond  of,  and  live  upon  meat  chiefly,  have 
short  second  stomachs ;  while  those  fond  of  breadstuff*,  vegetables,  and 
fruit,  have  longer  second  stomachs.  It  might  be  a  question,  whether  the 
change  of  diet  in  case  of  man  or  animals,  would  tend  to  alter  the  length 
cf  the  second  stomach.  It  is  said,  and  probably  with  truth,  that  the 
use  of  concentrated  food  tends  to  lessen  the  size  of  the  first  stomach. 

242.  The  reason  why  this  difference  should  exist  in  the 
length  of  the  second  stomach,  will  be  evident  if  its  use  be 
considered,  viz.,  in  the  first  place,  to  cause  the  food  to  under- 
go a  change  ;  and  in  the  second  place,  to  remove  the  proper 
parts  of  the  food  into  the  bloodvessels. 

The  more  waste  substance  found  in  the  food,  the  longer  should  the 
food  remain  in  the  second  stomach,  and  the  greater  must  be  its  length ; 
as  while  the  food  is  in  the  second  stomach,  it  is  gradually  moved  along 
by  the  action  of  the  muscular  coats;  if  the  food  require  to  be  acted 
upon  for  a  long  time,  the  tube  through  which  it  is  passing,  must  be  corre- 
spondingly large. 

243.  The  food,  which  in  the  first  stomach  has  passed 
through  the  first  process  of  digestion,  and  been  formed  into 
chyme,  passes  into  the  second  stomach  through  the  pylorus ; 
but  undergoes  no  change  till  it  has  been  mingled  with  three 
fluids, — the  pancreatic  juice,  the  bile,  and  the  gall. 

244.  TJie  Pancreas,  in  which  the  pancreatic  juice  is 
formed,  has  in  the  calf  the  name  of  "  sweetbread.'*'  It  is  a 
gland  (Fig.  95),  in  color,  external  surface,  and  internal  struc- 
ture, resembling  the  salivary  glands.  It  is  situated  across 
the  body  in  front  of  the  back-bone,  separated  from  it  by 
large  bloodvessels,  having  in  front  of  itself  the  lower  portion 
of  the  stomach  when  distended.  It  is  from  six  jp  ten  inches 
iu  length,  weighing  about  four  to  six  ounces.  Its  larger 
extremity,  called  the  head,  is  toward  the  right,  near  where 
its  tube  or  duct  opens  into  the  second  stomach. 

14* 


THE  DIGESTIVE  ORGANS-  [CHAP.  I. 

245.  The  fluid  formed  in  it,  is  somewhat  similar  in  gene- 
ral appearance  to  the  saliva  ;  but  differs  from  it  in  chemical 
character. 

The  quantity  of  pancreatic  juice  formed,  the  diseases  of  the  organ  or 
its  importance,  are  not  known. 

246.  The  Liver,  in  which  the  bile  is  formed,  is  the  largest 
gland  in  the  body.     Its  appearance,  size,  and  density,  are 
much  like  the  liver  of  the  hog.     Its  situation  is  in  the  ab- 
domen, immediately  beneath  the  diaphragm,  as  seen  in  Fig. 
96,  and  in  Fig.  97.  It  nearly  fills  the  middle  region  of  the  right 
half  of  the  body,  and  passes  across  the  centre  into  the  left 
half. 

It  therefore  occupies  more  space  than  is  usually  thought.  The 
position  it  occupies  is  constantly  changing  when  the  breath  is  drawn 
in  and  thrown  out ;  as  its  upper  surface  is  always  in  close  contact  with 
the  diaphragm  or  midriff,  and  it,  of  course,  is  acted  upon  by  all  those 
causes  of  pressure  and  displacement  which  affect  the  stomach. 

247.  Its  form  is  very  peculiar.    Above  it  is  arching  from 
all  its  borders,  and  below  is  concave  from  all  its  borders,  but 
not  in  a  degree  to  correspond  with  its  convexity  above.     Its 
edges  are,  therefore,  very  thin,  as  shown  in  figures  of  its 
sections.     In  the  centre  of  the  right  side  it  is  very  thick,  but 
from  that  point  to  its  extreme  left,  it  diminishes  in  thickness, 
presenting  a  wedge-like  form,  except  that  its  thickness  is 
diminished  from  its  under  side. 

248.  I  is  held  in  its  position  by  ligaments,  called  roots, 
which  attach  it  to  the  back-bone,  and  by  the  "  suction  "  of 
the  chest.     It  is  not  connected  with  the  diaphragm  in  the 
slightest  degree,  but  merely  lies  against  it. 

249.  It  is  composed,  like  other  compound  glands,  in  the 
first  place,  of  a  tube  which  divides  into  a  great  number  of 
branches  corresponding  with  the  large  size  of  the  liver,  the 
twigs  of  these  branches  terminating  in  clusters  of  crypto. 
The  tube  commences  at  the,  inner  surface  of  the  second 


SEC.  3.] 


SECOND  STOMACH,  LIVER,  ETC. 
Fig.  97. 


823 


Fig.  97. — Section  of  the  chest  and  upper  part  of  the  abdomen.  2,  Left  lung,  per- 
fectly filling  the  left  side — see  also  Lith.  PI.  3,  Fig.  1.  3,  Right  lung,  somewhat  broader 
and  shorter  than  the  left.  4,  The  left  or  back  heart,  cut  across  but  not  exhibiting  ita 
internal  divisions.  5,  Right  or  front  heart.  7,  Arch  of  the  aorta,  continued  back  of 
the  heart,  as  seen  by  the  dotted  lines.  8,  The  vena  cava  descendens.  8',  The  vena 
cava  ascendens,  viz.,  the  veins  through  which  the  blood  returns  to  the  heart.  9.  The 
opening  of  the  oesophagus  into  the  stomach— the  dotted  lines  exhibiting  the  direction 
of  the  lower  part  of  the~oesophagus,  behind  the  thin  point  of  the  liver.  10,  The  pylorus. 
Both  this  and  the  opening  at  9,  being  closed  when  the  stomach  is  distended  with  food, 
as  here  represented.  14,  The  larger  curvature  of  the  stomach,  as  from  9  to  10  is  the 
lesser  curvature.  11,  The  commencement  of  the  second  stomach,  called  the  duode- 
num. 12,  The  larger  lobe  of  the  liver — indistinctly  separated  from  the  lesser  lobe  13. 
15,  A  section  of  the  gall-bladder.  The  diaphragm  is  seen  arching  above  the  organs 
of  the  abdomen,  as  when  the  breath  is  thrown  out.  When  the  sides  of  the  diaphragm 
are  contracted  and  the  sides  of  the  abdomen  relaxed,  the  parts  below  are  pressed  down 
while  the  air  pressed  in  through  the  windpipe  presses  down  the  bottom  of  the  lungs, 
causin?  it  to  follow  the  depression  of  the  diaphrasrm,  the  movement  of  which  is  very 
slight  beneath  the  heart.  1,  Gives  the  form  of  what  is  called  the  thyroid  gland,  situated 
upon  the  w  ndpipe  6,  a  little  below  the  "  Adam's  apple."  [It  is  of  a  red-purple  color, 
softer  than  Jver,  somewhat  saddle-shaped.  It  receives  bloodvessels  and  nerves,  but 
has  no  tube  leading  from  it.  Its  use  is  not  known ;  and  though  in  external  appearance 
somewhat  representing  some  of  the  glands,  it  is  in  all  probability  wrongly  named.  It 
sometimes  enlarges,  producing  what  is  called  goitre,  broncocele,  swelled  neck.  One 
of  the  most  important  causes  of  this,  is  the  use  of  hard  water — as  in  passing  throu?h 
the  entire  United  States,  it  has  been  noticed  that  very  few  cases  of  goitre  are  found  in 
sections  where  the  water  is  soft ;  but  that  they  are  very  common  in  central  New- 
York,  and  other  sections  where  the  water  is  hard.  After  attention  had  been  arrested 
by  the  evident  fact,  it  was  also  found  to  be  the  case  in  Europe ;  in  some  sections  of 
which,  the  evil  is  much  more  extensive  than  here.  Other  causes  may,  and  doubtless 
do,  assist  to  produce  the  result.] 


stomach,  about  three  or  four  inches  from  the  pylorus,  and  is 
lined  by  a  continuation  of  the  lining  of  the  second  stomach. 


324  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

250.  The  liver  is,  of  course,  supplied  with  blood  to  form 
and  repair  itself  not  only,  but  also  to  form  the  bile.  But 
upon  examination,  the  liver  is  found  to  be  supplied  with  two 
kinds  of  blood,  which  is  not  the  case  with  any  other  part  of 
the  body  except  the  lungs.  One  of  these  kinds  is  the  same 
as  every  other  part  of  the  body  receives ;  but  by  a  singular 
arrangement,  all  the  blood  passing  to  the  stomach,  pancreas, 
second  stomach,  and  spleen,  and  not  used  in  them,  passes 
directly  to  the  liver  through  vessels  that  divide  and  subdivide 
in  every  part  of  it  (Lith.  PL  4,  Fig.  4). 

251.  Some  argue  that  the  liver  is  nourished  by  the  blood  first  men- 
tioned, and  the  bile  formed  from  the  blood  last  spoken  of,  while  some 
think  that  both  kinds  are  necessary  in  the  formation  of  bile.  Those 
who  think  the  bile  is  formed  only  from  the  blood  coming  from  the 
stomach,  &c.,  are  of  two  classes.  One  class  thinks  there  is  some  con- 
dition produced  in  the  blood  as  it  is  circulating  through  the  digestive 
organs,  which  renders  it  unhealthy,  or  unfit  to  go  into  other  parts  till  it 
has  been  acted  upon  by  the  liver,  and  sustain  their  opinion  by  the  fact, 
that  when  the  liver  is  unhealthy  and  does  not,  as  they  think,  purify  the 
blood,  the  whole  body  is  soon  enfeebled  and  indicates  symptoms  of  ill 
health.  The  other  class  thinks  that  the  bile  is  of  essential  service  in  the 
second  process  of  digestion,  and  that  the  reason  why  the  blood  from  the 
stomach,  &c.,  passes  through  the  liver  is,  that  the  quantity  of  blood 
supplied  to  those  organs  is  always  increased  before  there  is  any  cause 
for  the  fonnation  of  bile,  to  aid  in  the  second  process  of  digestion  ;  that 
therefore,  there  is  always  an  increased  circulation  of  blood  to  the 
stomach,  &c.,  before  the  liver  requires  an  increased  circulation,  which 
it  always  now  receives  when  needed,  as  increased  circulation  through 
the  stomach  necessarily  causes,  in  health,  an  increased  circulation  through 
the  liver. 

252.  Between  the  bloodvessels  and  tubes  or  ducts  of  the 
liver,  and  between  the  cryptse,  a  dense  substance  is  formed, 
called  the  parenchymateous  substance  of  the  liver,  the  whole 
is  then  covered  with  a  membrane   exceedingly  glairy,  its 
outer  surface  being  kept  moist  by  serous  fluid. 

253.  The  substance  formed  in  the  liver  is  called  the 


SEC.  3.]  SECOND  STOMACH,  LIVER,  ETC.  825 

bile;  it  is  almost  as  limpid  as  water,  of  an  orange-green 
color,  and  rather  sweetish  than  bitter. 

It  is  not  certain  whether  it  be  formed  constantly,  or  only  when 
necessary  in  the  digestion  of  food,  or  is  merely  increased  in  quantity 
then  ;  nor  is  it  certain  how  much  bile  is  formed  in  any  given  time.  In 
some  persons  there  seems  to  be  much  more  formed  than  in  others,  and  in 
the  same  person  different  quantities  at  different  times. 

254.  The  Gall  is   found  in  the  gall  bladder,  or  gall  cyst, 
which  is  of  a  pyramidal  form,  and  found  underneath  the  liver, 
(Fig.  95),  the  base  of  it  coming  to  the  edge  of  the  liver,  as 
indicated  in  Lith.  PI.  3,  Fig.  1 ;  it  is  furnished  with  blood  as 
other  parts  of  the  body.     A  tube,  called  the  gall  or  cystic 
duct,  leads  up  and  back  from  it,  and  then  downward  to  open 
into  the  tube  called  the  hepatic  duct,  leading  from  the  liver 
to  the  second  stomach.     The  gall  is  an  exceedingly  bitter 
fluid,  of  a  dark-green  color,  thick  or  ropy  in  consistence. 

It  passes  down  into  the  second  stomach,  as  some  believe,  because  it 
is  a  worthless  substance,  which  ought  to  be  cast  from  the  system,  and  as 
others  think,  because  it  aids  digestion. 

255.  Some  believe  that  the  gall  is  formed  in  the  liver  as  bile,  passes 
from  the  liver  and  through  the  branch  tube  into  the  gall  bladder,  where 
it  receives  its  bitter  and  other  gall  qualities  ;  while  others  think  that  the 
gall  bladder  is  a  great  cryptae,  the  inner  surface  of  which  forms  the 
gall.     And  it  would  seem  as  if  the  gall  bladder  could  as  easily  form  the 
entire  gall  as  add  bitterness  to  bile.* 

256.  Before  tracing  the  course  of  the  bile  in  the  second  stomach,  its 
action  upon  the  first  stomach,  and  its  presence  there  may  be  considered. 
The  distance  from  its  entrance  into  the  second  stomach  is  so  near  the 
pylorus,  that  it  would  seem  easy  for  the  bile  to  find  its  way  into  the  first 
stomach ;  but  it  is  seldom  found  there,  and  it  is  doubtful  whether  it  is 
ever  of  any  assistance  in  the  first  process  of  digestion.     Dr.  Beaumont 
noticed  it  in  the  first  stomach  in  but  very  few  instances,  when  he  could 
not  decide  against  its  utHity. 


*  The  common  idea  is,  that  bile  is  bitter,  but  if  it  were,  liver  would 
taste  bitter  when  eaten,  as  the  bile  could  not  be  entirely  washed  out. 
If  the  gall  be  allowed  to  run  over  meat  it  is  spoiled. 


328  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

257.  Pressure  upon  the  abdomen,  especially  forcible  pres- 
sure over  the  region  of  the  liver,  will  cause  the  gall  and  bile 
to  flow  into  the  second  stomach,  and  thence  backward  into 
the  first  stomach. 

Hence  when  a  person  vomits,  the  retchings  would  produce  this 
effect,  and  it  will  be  noticed  that  if  bile  or  gall  make  its  appearance,  it 
will  not  be  when  the  emetic  first  begins  to  act.  The  stomach,  there- 
fore, is  not  so  "bilious"  as  people  suppose.  There  maybe  bile  in  the 
stomach  when  vomiting  begins,  but  it  is  not  probable.  Nor  is  the  quan- 
tity ultimately  removed  to  be  judged  by  the  apparent  quantity,  for  a  little 
gall  will  bitter  and  color  a  large  quantity  of  fluid  or  other  substance.* 

258.  The  gray  paste  or  chyme,  differing  in  its  consistence 
and  qualities  according  to  what  it  has  been  formed  from,  re- 
ceives in  the   first  part  of  its  progress  through  the  second 
stomach,  the   pancreatic  juice,  the  bile  and  the  gall ;   and 
mingled  with  these,  it  is  slowly  pressed  on  by  the  contraction 
of  the  muscular  coats  of  the  intestines.     Thus  acted  upon,  it 
begins  to  undergo  a  change  ;  a  larger  or  smaller  portion  ex- 
hibiting a  color  and  consistence  which  varies  from  that  of  a 
thin  gruel  to  a  thick  cream.     Its  name  is  chyle,  the  lacteal 
(milk-like)  fluid,  the  white  blood,  &c.     It  contains  those  parts 
of  the  food  destined  to  form  the  blood. 

259.  It  is  removed  by  a  set  of  vessels  called  the  lacteals, 
which  commence  in  a  manner  which  has  as  yet  escaped  scru- 
tiny.    They  can  be  observed  quite  near  to  the  inner  surface 
of  the  second  stomach,  from  whence  they  pass  through  the 

*  Another  common  error  is,  that  whatever  is  thrown  off  from  the 
stomach  was  there  when  the  emetic  was  taken,  and  "the  necessity  for  the 
emetic  is  judged  by  the  quantity  removed.  This  is  the  case  with  certain 
kinds  of  emetics  ;  for  instance,  water.  But  usually  the  first  effect  of  an 
emetic  is  to  cause  the  sides  of  the  stomach  to  remove  into  it,  from  the 
blood  circulating  around  the  stomach,  a  quantity  of  fluid  substance  which 
is  then,  with  any  other  contents  of  the  stomach,  thrown  off.  Emetic 
after  emetic  may  be  given,  as  has  been  done,  till  death  is  caused,  and 
yet  from  the  stomach  something  may  be  thrown  off  each  time.* 

•  Diseases  and  peculiar  conditions  of  the  liver,  will  be  spoken  of  when  it  is  again 
treated  upon  as  one  of  the  class  of  excreting  organs. 


SEC.  3.]  SECOND  STOMACH,  LIVER,  ETC.  327 

muscular  coat,  and  are  received  between  the  two  thicknesses 
of  the  mesentery,  which  (Fig.  96)  stretch,  ribbon-like,  from 
the  back-bone  to  the  intestine.  There  are  millions  upon 
millions  of  these  roots,  which  immediately  begin  to  unite 
with  each  other,  until  at  last  they  all  terminate  in  a  single 
tube  or  duct  called  the  thoracic  (chest)  duct.  There  are 
many  more  roots  of  lacteals  in  the  upper  part  of  the  small 
intestines  than  farther  on,  for  the  second  process  of  digestion 
goes  on  more  rapidly  in  the  upper  than  in  the  lower  part  of 
the  canal,  and  of  course  more  chyle  requires  more  lacteals  to 
remove  it.  (Fig.  109,  B). 

260.  In  the  course  of  the  lacteals,  there  are  small  round- 
ish or  oblong-shaped  organs  (Fig.  98)  called  mesenteric  or  lac- 
teal  glands,  but  their  intimate  structure  or  particular  use  is 
not  known.  The  chyle  seems  to  change  its  color  somewhat 
as  it  is  passing  through  them,  and  they  therefore  produce 
some  effect  upon  it. 

Fig.  98. 


Fig.  98.— Lacteal  eland,  much  magnified,  a,  a,  a,  Vessels  opening  into  it.  6,  A,  Vc» 
eels  leading  out  from  the  gland,  d,  Parenchymatous  substance  of  the  gland,  e,  c,  «, 
Bloodvessels  leading  to  and  from  the  gland. 

261.  The  thoracic  duct  commences  just  below  the  dia- 
phragm, by  the  pressure  of  which  it  appears  to  be  enlarged. 
Above  the  diaphragm,  it  passes  up  in  front  of  the  back-bons, 


328  THE  DIGESTIVE  ORGANS.  [CHAP.  I, 

and  rather  upon  its  right  side,  till  it  arrives  at  the  centre  of 
the  back,  when  it  winds  across  to  the  left  side  of  the  centre 
upon  which  it  is  situated,  till  it  arrives  in  the  region  of  the 
neck,  where  it  turns  forward,  and  bending  downward,  empties 
its  contents  into  the  vein  at  the  angle  where  tie  vein  from  the 
left  arm  unites  with  the  left  jugular  vein.  Its  size  is  small, 
not  being  as  large  as  a  common  quill,  but  it  is  a  canal  of 
much  consequence. 

Why  it  should  pass  such  a  distance  before  emptying  itself,  is  yet  a 
mystery ;  without  a  doubt,  some  excellent  purpose  is  served. 

262.  That  portion  of  the  chyme,  bile,  gall,  pancreatic  juice, 
&c.,  which  has  not  undergone  the  change,  passes  through 
the  entire  length  of  the  second  stomach,  into  the  large  intes- 
tine, which  commences  (Lith.  PI.  3,  Fig.  1),  in  the  lower  and 
right  side  of  the  abdomen.  The  opening  into  this  is  a  little 
above  its  commencement  (Fig.  99).  The  part  below  is 
called  the  caecum,  and  an  appendage  to  this,  the  use  of  which 
is  not  known,  is  called  the  vermiform  (worm-like)  append- 
age. Collections  are  very  apt  to  take  place  in  the  coecum, 
and  more  especially  in  the  appendage,  and  when  the  food  has 
not  been  thoroughly  masticated,  serious  harm  is  sometimes 
produced  by  bits  of  substances  lodging  there. 

Fig.  99. 


Fig.  99— c,  Coecum  opened,  a,  Valve-like  fold  for  closing  the  opening  6,  from  tho 
last  part  of  the  second  stomach/,  o,  Opening  into  the  vermiform  appendage  v.  d, 
Ascending  colon  entire. 


SEC.  3.]  SECOND  STOMACH,  LIVER,  ETC.  329 

263.  At  the  opening  from  the  ileum,  into  the  caecum,  a 
"  fold"  of  the  lining  of  the  latter,  is  arranged  so  as  to  act 
like  a  valve,  and  prevent  substances  from  passing  backward 
beyond  that  point.     Commencing  from  the  coecum,  the  colon 
passes  up  till  beneath  the  lower  and  front  thin  edge  of  the 
liver,  when  it  curves  and  passes  across  the  body,  in  the  situ- 
ation  where  bilious  colic  is  usually  felt,  viz.,  in  front  of  the 
duodenum,  below  or  in  front  of  the  most  dependent  portion  of 
the  stomach,  and  above  the  jejunum  (Fig.  96).    At  the  left  side 
it  turns  abruptly  downward,  (PL  3,  Fig.  1«)  is  seen  situated  a 
little  behind  the  small  intestines.     When  it  is  traced  as  far 
as  within  the  hip,  it  is  observed  to  make  two  curves,  called 
the  sigmoid  (S-like)  flexure  of  the  colon,  by  which  it  arrives 
in  front  of  the  sacrum.    The  remaining  portion  being  straight, 
is  called  the  rectum.     The  coacum  and  rectum  are  quite 
closely  confined  in  their  places,  but  the  remaining  parts  of 
the  large  intestine  are  allowed  a  great  deal  of  motion,  which 
is  continually  produced  by  one  cause  or  another  of  pressure. 

264.  Those  parts    are   constructed  much  in   the   same 
manner  as  the  second  stomach,  except  that  the  longitudinal 
muscular  fibres  are  gathered  into  three  bands,  the  circular 
fibres,  though  found  in  the  whole  extent,  are  much  more 
numerous  at  frequent  points,  causing  the  color  to  appear  like 
a  series  of  pouches ;  the  inner  surface  resembles,  though  some- 
what different,  the  lining  of  the  second  stomach  ;  the  lacteals 
are  fewer  in  number,  and  denied  by  some  to  exist. 

265.  All  the  organs  concerned  in  the  second  process  of  digestion  re- 
quire a  free  supply  of  good  blood,  nervous  influence,  and  the  indirect  ac- 
tion of  the  mind.  The  performance  of  their  office  will  then  depend 
upon  the  perfection  of  the  process  in  the  first  stomach.  Nothing  further 
need  be  now  said  in  respect  to  food,  except  to  show  the  importance  of 
having  a  greater  or  less  portion  of  waste  substance  combined  with  it. 

266.  Every  organ  suffers  if  it  be  not  exercised  in  accor- 
dance with  the  intentions  of  nature. 


330  THE  DIGESTIVE  ORGANS.  [CHAP.  I. 

She  has  given  to  man  a  stomach,  differing  in  size  in  different  persons. 
The  muscular  fibres  of  it  can  act  with  more  energy  when  it  is  nearly 
full,  as  they  can  at  best  contract  not  more  than  half  their  length  ;  and 
muscles  are  most  effective  when  they  begin  to  contract.  At  times  only 
a  small  amount  of  food  is  needed,  and  that  it  should  be  combined  with 
waste  substance,  producing  bulk,  is  evident  from  the  fact,  that  in  summer, 
when  little  food  is  required,  either  to  warm  or  repair  the  system,  (for  a 
person  feels  languid  and  cannot  exercise  as  energetically  as  in  cold 
weather,)  nature  furnishes  vegetables  and  fruit,  which  contain  but  little 
food  and  much  waste,  and  the  wanner  the  weather,  the  more  luxuriant  is 
vegetation.  By  exercise,  also,  the  muscular  fibres  of  the  stomach  and 
second  stomach  become  strong  ;  and  as  the  action  of  every  part  of  the 
body  is  much  influenced  by  habit,  it  is  important  to  secure  the  regular 
action  of  these  organs. 

267.  The  comparative  amount  of  waste  substance  to  be  used  by  dif- 
ferent persons  is  different,  and  must  be  estimated  by  each  individual  upon 
principles  set  forth  when  the  digestive  canal  is  hereafter  again  noticed  as 
an  excreting  organ. 

In  conclusion,  of  the  digestive  organs  it  may  be  laid  down 
as  a  golden  rule,  that  ALMOST  EVERY  THING  is  GOOD  FOR  FOOD, 

IF  ONLY  EATEN  IN  ITS  SEASON,  AT  A  PROPER  TIME,  AND  IN  A 
PROPER  MANNER,  PROVIDED  A  PERSON  WILL  NOT  EAT  TOO 
MUCH  OF  IT.  MOST  PEOPLE  EAT  TOO  MUCH. 


CHAPTER  II. 

THE   CIKCULATOKY   OEGANS. 

General  Observations. 

268.  These  parts  of  the  body  have  much  to  accomplish.     That  every 
part  may  be  of  a  healthful  temperature,  there  must  be  a  very  rapid  pas- 
sage of  fluid  through  every  part,  that  the  heat  produced  in  one  part  may 
be  distributed  to  other  portions  of  the  system  ;  for  as  soon  as  the  circula- 
tion languishes,  the  body  begins  to  suffer  from  unnatural  temperatures. 

269.  As  some  parts  are  at  times  exposed  to  lose  heat  much  faster 
than  other  parts,  there  must  be  an  arrangement  for  increasing  the  quan- 
tity of  heat-giving  fluid  the  parts  naturally  receive. 

270.  That  every  part  may  be  properly  nourished,  it  must  constantly 
be  visited  by  the  nourishing  fluid  of  the  bloodvessels ;  for  of  certain  sub- 
stances which  the  part  requires,  the  blood  contains  but  a  very  limited 
supply  ;  therefore  at  times  a  very  large  amount  of  blood  will  flow  through 
a  part  before  it  has  its  needs  satisfied  ;  and  as  each  part  requires  much 
more  nourishment  at  one  time  than  at  another,  there  must  be  an  arrange- 
ment for  increasing  the  quantity  of  blood  the  part  shall  receive. 

271.  That  the  waste  substance  constantly  produced  in  the  body  may 
be  as  constantly  removed,  an  active  circulation  of  blood,  increased  as  any 
part  cular  part  shall  require,  will  be  necessary. 

272.  That  every  part  may  be  cooled  as  the  case  may  require,  it  will 
be  necessary  that  the  circulation  be  active,  and  increased  or  diminished, 
generally  or  particularly,  with  the  utmost  accuracy. 

273.  To  accomplish  this  purpose,  two  sets  of  fleshy  tubes  will  be  ne- 
cessary, the  divisions  of  which  must  be  so  minute  that  the  life-giving 
blood  may  visit  every  part.      One  set  will  be  required  for  the  blood  to 
pass  to  every  part  through,  and  another  set  for  it  to  pass  back  through. 

274.  But  as  the  tubes  are  exceedingly  small  in  most  of  their  branches, 
aad  liable  to  be  bent  and  pressed  upon,  there  must  be  some  force  which 


332  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

shall  drive  the  blood  in  its  constant  and  rapid  course — a  force  which  shall 
be  more  or  less  active,  as  the  case  requires.  For  this,  nothing  will  be 
better  than  a  muscular  bag  or  pouch  ;  for  by  the  contraction  of  its  fibres, 
its  contents  could  be  forced  to  the  extremities  of  the  body  with  the  de- 
sired rapidity. 

275.  The  action  of  this  muscular  bag,  called  a  heart,  must  be  con- 
stant as  ever  during  the  night,  and  in  the  soundest  sleep  there  is  a  great 
deal  of  action  necessary  in  the  body,  and  of  course  blood  is  required,  as 
well  as  also  to  keep  the  body  wann.      The  influence  which  controls  the 
circulation  cannot,  therefore,  be  exercised  by  the  mind,  but  is  derived 
from  the  organic  nervous  system.     There  is,  however,  no  part  of  the  body 
which  exhibits  more  clearly  than  the  organs  under  consideration,  the.  in- 
fluence of  the  mind.     The  flush  on  the  cheek,  the  quickened  pulse,  &c., 
produced  by  the  emotions,  will  convince  any  one  that  the  state  of  the 
mind  is  an  important  matter  when  treating  upon  the  causes  which  com- 
pel the  blood  to  quicken  or  delay  its  speed. 

276.  There  are  two  ways  by  which  the  quantity  of  blood  circulating 
to  any  part  may  be  increased ;  it  can  be  done  either  by  increasing  the 
power  and  rapidity  of  the  heart's  action,  or  by  enlarging  the  capacity  of 
the  vessels  of  a  part.     If  the  first  thing  be  done,  the  circulation  of  the 
blood  in  all  parts  is  increased  ;  if  the  last  thing  be  done,  the  circulation 
in  only  the  desired  part  is  increased. 

277.  Sometimes  one  of  these  ways,  sometimes  the  other,  sometimes 
both  are  necessary.    An  additional  cause  may  sometimes  be  in  action, 
viz.,  at  the  same  time  the  bloodvessels  of  one  part  are  enlarged,  those  of 
some  other  part  or  parts  may  be  lessened. 

278.  But  as  the  whole  apparatus  of  the  circulatory  organs  has  refer- 
ence to  the  blood,  viz.,  to  keeping  it  moving  through  the  various  parts  of 
the  body,  and  in  the  quantity  the  parts  require,  it  will  be  proper  in  the 
first  place  to  consider  the  blood. 


The  Blood. 

279.  Blood  is  obtained  from  three  sources,  strictly  speaking.     The 
food,  the  drink,  and  the  air  we  breathe ;  but  it  will  be  proper,  also,  to 
say  that  the  blood  is  obtained  from  the  decomposition,  or  wearing  out  of 
the  body,  which  is  constantly  taking  place. 

280.  The  quantity  of  blood  is  constantly  varying  according  to  the 
quantity  of  substance  added  to  it  from  the  food,  the  drink,  the  wearing 


GENERAL  OBSERVATIONS.  333 

out  of  the  body,  and  from  the  air,  or  taken  from  it  to  nourish  the  body, 
to  cool  the  body,  or  by  the  excreting  organs. 

281.  The  thickness  of  the  blood  varies  very  much;  sometimes  it  is 
very  thin  and  watery,  at  another  it  contains  much  solid  substance  in  a 
state  of  solution.     If  a  person  quench  his  thirst  by  a  large  draught  of 
water,  the  blood  is  thinner  by  so  much  ;  if  he  perspire  freely  and  do  not 
drink,  his  Mood  becomes  thicker. 

282.  The  color  of  the  blood  varies.     In  the   body  oruinarily,  the 
blood  is  considered  to  be  of  two  colors,  a  crimson  red,  viz.,  blood  color, 
and  a  dark  red  or  deep  purple,  sometimes  called  black.    It  is  red  in  those 
vessels  through  which  it  goes  out,  and  purple  in  those  liirough  which  it 
comes  back.     But  the  brightness  of  the  red  and  the  depth  of  the  purple 
depend  upon  a  variety  of  causes.     The  change  of  color  from  red  to 
purple  takes  place  in  every  part  of  the  body,  and  of  course,  must  be  pro- 
duced by  some  cause  which  is  operating  in  every  part ;  and  as  this 
change  takes  place  in  parts  which  seem  almost,  if  not  entirely  at  rest, 
the   cause  would  seem  to  be  some  one  which  had  reference  to  the  pro- 
duction of  heat,  especially  as  it  will  be  found  that, 

283.  The  blood  changes  from  purple  to  red  in  the  lungs,  and  upon 
the  perfection  with  which  this  takes  place,  will  depend  the  heat  of 
the  body.     The  change  of  color  may  be,  and  doubtless  is,  an  accidental 
thing ;  but  as  the  proper  color  is  always  indicative  of  proper  blood,  it  is 
very  common  to  designate  the  qualities  of  the  blood  by  its  color. 

284.  The  change  in  the  color  of  the  blood  from  red  to  purple  will 
depend  upon  the  quality  of  the  blood,  and  the  activity  of  any  part 
through  which  it  passes.     The  more  active  any  part  is,  the   deeper 
purple  will  the  blood  assume  on  its  return.     The  more  active  the  body  is 
the  warmer  is  it ;  the  more  heat  is  there  produced.     This  would  seem  to 
show  that  those  same  changes  which  produce  a  change  in  color,  produce 
heat  also. 

28  5,  The  change  in  the  color  of  the  blood  from  purple  to  red,  de- 
pends upon  the  quality  of  the  blood,  and  the  quantity  and  quality  of  the 
air  acting  on  the  blood  in  the  lungs. 

286.  The  quality  of  the  blood  is  constantly  varying.  From  the  food, 
it  receives  ingredients  to  nourish,  and  fuel  to  h.eat  the  system,  and  from 
what  is  eaten,  many  things  pass  into  the  bloodvessels  and  become  a 
part  of  the  blood,  which  are  not  for  its  good.  Its  nourishment  is  contin- 
ually taken  from  it  by  the  demands  of  the  parts  through  which  it  is  pass- 
ing, and  its  fuel  must  be  constantly  used  to  produce  heat.  The  wear  of 
the  body,  or  its  decomposition,  is  constantly  adding  to  it  substance,  which 


334  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

it  is  the  duty  of  the  excreting  organs  to  remove.  This,  they  sometimes 
do  promptly,  sometimes  tardily,  so  that  sometimes  the  blood  never  con- 
tains more  waste  substance  than  is  for  the  health  of  the  system,  and 
'sometimes  it  is  diseased  by  the  slackness  of  the  excreting  apparatus. 
The  quality  of  the  blood  usually  varies  as  its  color. 

287.  The  composition  of  the  blood  varies  as  does  its  color  and  quality  ; 
in  a  general  view  it  is  very  similar  to  the  chyle,  containing  the  various 
constituents  which  enier  into  the  form  of  the  body,  and  many  which  have 
served  their  purpose  in  that  respect.  It  will  not  be  worth  while  to  exam  ne 
it  minutely.  If  it  be  allowed  to  remain  quiet  a  few  moments  after  it  is 
drawn,  it  will  separate  into  a  dirty  yellow  fluid,  and  a  red  clot  which 
sinks  in  it,  the  fluid  is  called  serum,  and  sometimes,  the  white  blood.  If 
the  clot  be  thoroughly  washed  with  water,  it  will  become  white,  and  it 
will  be  found  that  its  red  color  was  given  to  it  by  blood -globules,  as  they 
are  called,  that  is,  substances  of  a  rounded  form,  like  balls  somewhat 
flattened.  They  are  larger  than  many  of  the  small  vessels,  and  cannot, 
if  they  be  healthy,  pass  into  them.  What  particular  office  they  fulfil  is 
not  known.  If  their  duty  had  been  one  half  what  has  been  assigned  to 
them  by  the  conjecture  of  one  person  or  another,  there  would  have  been 
but  little  use  for  any  thing  else  in  the  body. 

2fc'8.  It  is  a  question  of  great  moment,  and  has  never  been  settled, 
whether  the  blood  contains  the  ingredients  that  every  part  requires,  and 
which  therefore,  has  only  to  separate  from  the  rest  of  the  blood,  that 
which  it  wants,  ready  formed  for  its  use,  or  contains  only  the  elements  in 
a  certain  compound  state,  which  each  part  is  to  take  from  the  blood,  and 
combine  in  that  way  which  adapts  them  to  its  need.  It  is  also  a  question 
of  a  similar  kind,  whether  the  substances  to  be  removed  from  the  blood, 
exist  in  it  in  the  same  combination  as  when  removed,  and  are  therefore 
only  removed  by  the  excreting  organ,  or  in  such  a  combination  that  the 
excreting  organ  is  obliged  to  form  a  new  substance,  taking  from  the  blood 
only  a  part  of  several  different  compounds. 

289.  Before  considering  the  apparatus  of  circulation,  it  will  be  im- 
portant to  take  notice  of  a  fact  developed  in  the  course  of  the  last  few 
paragraphs,  viz.,  that  the  blood  in  passing  through  any  organ,  whether 
active  or  to  all  appearance  inactive,  is  changed  in  color  and  qualities  to 
a  certain  degree  ;  to  be  restored  from  which  condition  it  is  necessary 
the  blood  should  be  exposed  to  the  air — for  which  purpose  the  lungs  are 
provided. 

290.  Another  two  sets  of  vessels  will  be  required,  viz.,  one  set  through 
which  the  blood  shall  be  carried  into  the  lungs,  to  be  acted  on  by  the 


SEC.  1.]  THE  HEART.  835 

air,  and  another  set  to  bring  the  blood  back  after  it  has  been  acted  upon; 
and  a  forcing  apparatus  or  heart,  will  also  be  required  to  drive  the  blood 
through  the  lungs. 

291.  The  importance  of  this  last  arrangement  is  very  evident,  when 
from  any  cause  the  lungs  fail  to  perform  their  duty,  and  it  is  all  the  same 
as  if  the  blood  did  not  go  through  them  ;  the  vigor  of  the  system  is  im- 
paired, its  warmth  is  lessened,  the  mind  is  oppressed,  the  skin  becomes 
sallow  or  livid-like,  digestion  fatis,  and  every  part  of  the  sy&^cm  bears 
witness  to  the  need  of  the  action  of  air  upon  the  blood. 

292.  The  blood  which  returns  from  the  lungs,  is  also  warmer  than  it 
was  when  it  entered  them,  which  is  undeniable  proof  of  the  utility  of  the 
lung- circulation,  as  it  is  sometimes  called. 

293.  There  are,  therefore,  said  to  be  two  circulations — the  greater 
and  the  lesser ;  but  in  fact  there  is  but  one  circulation,  viz.,  as  repre- 
sented in  Lith.  PI.  4,  Fig.  2,  the  blood  is  thrown  out  into  the  body, 
from  which  so  much  as  is  not  used,  with  the  waste  of  the  system  re- 
turns ;  not  to  the  same  heart  from  which  it  went  out,  but  the  heart  which 
throws  it  into  the  lungs,  from  which  organs  it  passes  to  the  heart  from 
which  it  was  considered  to  start,  and  from  which  it  is  again  poured  out. 
It  thus  passes  a  continual  round  until  it  is  somewhere  used,  when  it 
occupies  a  stationary  position  for  a  longer  or  shorter  time,  and  then 
comes  back,  having  served  its  purpose,  into  the  bloodvessels  ;  and  again 
pabsses  the  rounds  perhaps  once,  perhaps  a  thousand,  perhaps  a  million 
of  times,  till  it  is  cast  out  of  the  system.     The  power  which  produces 
this  motion  of  the  blood,  may  next  attract  attention. 


SECTION  1. — The  Heart. 

2a4.  What  is  usually  so  called,  is  in  fact  composed  of  two 
hearts,  viz.,  the  heart  that  drives  the  blood  through  the  body, 
and  the  heart  that  throws  the  blood  into  the  lungs  (Fig.  100). 

Like  two  houses  under  one  roof,  they  are  placed  together  for  the 
purpose  of  saving  substance  in  their  structure  ;  but  they  have  no  farther 
connection  with  each  other  (Fig.  101).  In  some  animals  the  hearts  are 
separated  for  a  short  distance,  as  in  the  dugong. 

295.  The  hearts  are  muscular  bags  or  sacs,  with  very 
thick,  strong  sides ;  the  fibres  interlacing  in  every  possible 


880  THE  CIRCULATORY  ORGANS.  [CHAP.  IK 

Fig.  100. 


Fig.  100.— The  two  hearts  in  contact.  R,  A,  Right  auricle.  R,  V.  Right  ventricle. 
L,  A,  Left  auricle.  L,  V,  Left  ventricle.  A,  A,  Aorta.  V,  V,  Veins.  P,  A,— P,  A, 
Pulmonary  arteries. 


direction,  leaving  but  a  small  cavity  of  from  one  to  three 
ounces  capacity  within. 

The  left  or  back  heart  is  much  the  thicker  and  stronger,  as  it 
should  be,  its  duty  being  to  throw  the  blood  to  the  extremities  of  the 
body  ;  while  the  right  or  front  heart  has  only  to  force  the  blood  through 
the  neighboring  lungs. 

296.  Each  heart  is  composed  of  two  parts  (Fig.  101). 
The  upper  part  is  called  the  auricle  ;   it  is  much  thinner  and 
weaker  than  the  lower  part,  which  is  called  the  ventricle. 

The  duty  of  the  upper  part  is  merely  to  force  the  blood  down  into 
th«  ventricle  ;  and  some  suppose  it  is  not  usually  active  in  performing 
this  duty,  but  that  the  blood  rushes  into  the  ventricle  as  it  opens. 

297.  Between  the  auricle  and  ventricle  of  the  right  heart, 
there  are  found  valves  as  they  are  called — their  particular 
names  being  the  tricuspid  (three-pointed)  valves.     They  are 
tendinous  substances,  attached  round  the  opening  between  the 
auricle  and  ventricle  (Fig.  102).    They  are  quite  smooth,  and 
entire  near  the  opening ;  but  a  little  distance  from  it  they  are 


SEC.  1.]  THE  HEART.  »B7 


Fig.  101.— Ideal  representation  to  show  the  facts  of  the  circulation  <rf  the  heart. 
Through  V,  V,  the  blood  passes  into  R,  A,  from  which  it  passes  into  R,  V,  and  goes 
out  through  P,  a.  Coming  back  through  P,  V,  into  L,  A,  it  passes  on  into  L,  V,  from 
which  it  goes  out  through  A. 

composed  of  a  great  number  of  cords,  which  are  connected 
with  short,  fleshy  columns  on  the  inside  of  the  ventricle,  oppo- 
site to  the  opening.  These  fleshy  columns  are  muscular,  and 
by  proper  relaxation  allow  the  valves  to  close  the  opening,  or 
draw  them  into  the  ventricle,  as  the  case  may  require. 

298.  By  the  situation  of  these  valves  it  is  seen  that  the  blood  will  be 
allowed  to  pass  through  the  opening  ki  one  direction  only,  viz.,  from  the 
auricle  into  the  ventricle.  A  similar  arrangement  exists  in  the  left  heart, 
except  that  there  are  two  valves,  called  mitral  (from  their  form  resem- 
bling a  bishop's  mitre). 

299.  At  the  opening  leading  out  of  the  ventricle  (Fig. 
103)  there  are  three  half-moon  shaped  valves,  without  ten- 
dons or  fleshy  columns  to  move  them,  but  depending  entirely 
upon  the  pressure  of  the  blood. 

When  by  contraction  of  the  heart,  blood  is  forced  against  the  inside 
of  the  tricuspid  and  mitral  valves,  and  causes  them  to  close  the  opening 
into  the  heart,  the  semi-lunar  (half-moon)  valves  are  raised  by  the  pres- 

15 


338 


THE  CIRCULATORY  ORGANS. 
Fig.  102. 


[CHAP.  ii. 


Fig.  102.— The  letters  exhibit  the  same  parts  as  before,  except  that  V,  represent* 
the  mitral  valves.    No  piece  of  the  heart  is  removed,  the  heart  being  merely  cut  open. 

Fig.  103. 


Pig.  103.— The  dart  shows  the  direction  of  the  current.  By  the  sides  of  the  dart  re- 
presentations of  the  open  semi-lunar  valves  are  seen.  When  closed,  the  edges  overlap 
wach  other,  while  between  the  edge  and  the  side  of  the  vessel  the  valve  "  bags  "  down. 

sure  upon  their  inner  or  under  surface,  and  the  blood  passes  through  be- 
tween them ;  but  vice  versa,  when  the  contracted  heart  begins  to  relax 
or  enlarge  and  open  the  tricuspid  and  mitral  valves,  the  semi-lunar  valves 
are  immediately  closed  by  the  pressure  upon  their  upper  surface  of  the 
blood  attempting  to  pass  back. 


SEC.  l.J  THE  HEART.  339 

Frequency  of  Pulsations. 

300.  The  number  of  contractions  of  the  heart  per  minute 
can  be  counted  either  by  feeling  the  pulse,  or  by  placing  the 
ear  upon  the  chest  and  listening  to  the  pulsations,  as  they 
are  called,  of  the  heart.    They  will  vary  in  different  persons, 
in  the  same  person  at  different  periods  of  life,  and  in  different 
states  of  health,  and  according  to  the  exercise. 

301.  In  some  persons  in  the  prime  of  life,  the  pulse  beats 
but  50  times  per  minute,  in  others  it  is  regular,  and  100  per 
minute.     In  the  female  it  is  quicker  than  in  the  male,  all 
other  things  being  equal.     In  infancy  it  is  120, 110,  100 ;  in 
old  age,  30,  50,  60 ;  in  prime  of  life  it  averages  75  for  men, 
80  among  women. 

If  we  say,  however,  64  for  ease  of  computation,  the  result  will  be 
astonishing,  counting  also  that  the  heart  throws  out  but  one  ounce  of  blood 
each  "beat."  This  will  give  64  ounces,  or  four  pounds  per  minute, 
240  Ibs.  per  hour,  or  5760  Ibs.  in  the  course  of  a  day  and  night,  and  the 
same  amount  which  one  heart  throws  into  the  lungs  the  other  heart 
throws  into  the  body.  But  the  labor  of  one  heart  at  half  its  true  amount, 
is  moving  nearly  three  tons  of  blood  per  day,  or  if  the  amount  be  com- 
puted in  quantity,  240  pounds  may  be  considered  as  240  pints ;  120  qts. ; 
30  galls.,  or  a  barrel  of  blood  in  the  course  of  an  hour. 

302.  The  importance  of  the  heart  is  altogether  beyond  ordinary 
thought.  Its  labors  are  truly  amazing,  and  the  mind  is  almost  lost  in 
wonder  when  it  considers  how  small  the  heart  is,  hardly  larger  than  a 
man's  fist,  beating  on  from  infancy  till  death,  without,  in  any  case,  an 
irregular  pulsation,  now  quick,  now  slow,  but  always  right ;  and  yet  how 
delicate  it  is  made  in  some  of  its  parts !  Why  does  it  not,  like  the 
works  of  man,  fail  at  some  point  1 

303.  The  heart  occupies  a  position  in  the  chest,  as  in 
Fig.  97.  Its  point  or  apex  is  situated  in  the  left  side,  within 
the  space  between  the  cartilages  of  the  sixth  and  seventh 
true  ribs,  at  the  point  against  which  the  heart  is  felt  beating, 
and  which  is  usually  thought  to  be  about  the  centre  of  the 
heart,  but  is  its  extreme  left  and  lower  point,  The  base  or 


340  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

roots  of  the  heart  are  near  to  the  back-bone,  and  back  of  the 
breast-bone.  It,  therefore,  is  placed  in  an  oblique  manner  in 
the  chest.  It  partially  rests  below  upon  the  central  part  of 
the  diaphragm,  and  is  partly  supported  by  tendinous  roots, 
which  connect  it  with  the  back-bone,  and  partly  by  suction 
of  the  chest. 

304.  The  heart  is  surrounded  by  the  "heart-case"  or 
pericardium,  a  strong  fibrous  pouch,  used  frequently  as  a 
money-purse.     It  is  not  connected  with  the  heart  except  at 
the  roots.     It  is  lined  by  a  serous  membrane,  which  also 
covers  the  heart.     Its  free  surface  is  moistened  by  a  small 
but  sufficient  quantity  of  serous  fluid.      It   sometimes  in- 
creases very  much,  producing  dropsy  of  the  heart. 

305.  Upon  each  side  of  the  heart,  connected  with  the 
back-bone,  the  breast-bone,  and  the  diaphragm,  thus  dividing 
the  chest  into  three  apartments,  is  found  what  is  called  the 
mediastinum,  as  if  the  two  made  but  one. 


SECTION  2. — The  Bloodvessels. 

A.   The  Arteries. 

306.  The  arteries  are  the  bloodvessels  which  lead  out 
from  the  heart  (Lith.  PL  4,  Fig.  1). 

They  must  be  so  formed  that  they  will  allow  or  assist  the  blood  to 
pass  easily  through  them  to  every  part  of  the  body. 

307.  They  are,   therefore,    formed   of  three   coats,   the 
outer  one  being  dense,  firm,  and  protective,  in  such  manner 
that  when  the  artery  is  cut  across  it  will  remain  open  to  a 
considerable  degree,  much  like  a  quill,  though  the  sides  of 
the  artery  are  not  so  unyielding  as  the  sides  of  a  quill. 

This  is  as  it  should  be,  for  the  bloodvessels  are  constantly  subject  to 
pressure  by  one  cause  and  another.  The  outer  coat  is,  however,  yielding 
to  a  certain  degree. 


SEC.  2.]  THE  BLOODVESSELS.  341 

308.  The  middle  coat  is  composed  of  yellow  elastic  fibres, 
which  some  think  actively  contractile. 

By  means  of  this,  the  diameter  of  the  arteries  is  considerably  lessen- 
ed when  they  are  cut  across. 

309.  The  inner  coat  of  the  arteries  is  a  very  smooth,  deli- 
cate membrane,  a  continuation  of  that  which  lines  the  heart. 

310.  In  the  next  place,  the  arteries  branch  from  each 
other,  at  acute  angles  (Fig.  104). 

Fig.  104. 


Except  in  case  of  a  few  large  ones  near  the  heart,  which  are  so  ar 
ranged,  that  the  blood  flows  into  them  in  the  easiest  manner. 

311.  In  the  last  place,  the  branches  of  the  arteries  open 
into  each  other,  in  many  places. 

By  this  means,  the  blood  can  be  supplied  to  various  parts,  by  various 
channels  (Lith.  PI.  4,  Fig.  1) ;  as  when  a  street  is  obstructed,  a  person 
can  drive  through  a  side  street,  and  come  back  beyond  the  obstruction, 
so  it  is  with  the  blood,  which  sometimes  goes  a  long  way  round,  but 
with  such  rapidity,  that  no  inconvenience  is  suffered. 

312.  The  arteries  are  almost  infinite  in  number,  and  found  in  evejry 
part  of  the  body,  larger  and  more  numerous  in  some  parts  than  others, 
which  is  because  some  parts  require  more  blood  than  others.  They  are 
called  by  two  different  general  names,  according  to  their  destination,  and 
by  different  particular  names,  according  to  their  situation. 

313.  The  pulmonary,  or  lung  arteries,  is  the  name  given 
to  those  which  are  destined  to  lead  the  blood  into  the  lungs. 

The  blood  which  they  contain  is  not  for  the  purpose  of  nourishing 
the  lungs,  but  is  to  be  acted  upon  by  the  air  drawn  into  the  lungs,  and 
thus  fitted  to  serve  the  wants  of  the  body. 

314.  The  lung  arteries  commence  by  a  single  artery  at 
the  top  of  the  ventricle  of  the  right  heart,  half-moon  or  semi- 


342  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

lunar  valves  being  found  at  its  commencing  point.  By  their 
action,  the  blood  once  received  by  the  artery  can  never  go 
back,  but  its  course  must  be  "  onward."  The  artery  is  very 
short,  before  it  divides  into  two  grand  branches  (Lith.  PL  3, 
Fig.  2),  one  leading  to  the  right,  the  other  to  the  left  lung, 
wbich  is  entered  by  the  side  of  the  windpipe,  at  every  di- 
vision of  which,  the  pulmonary  artery  divides,  and  thus  visits 
every  portion  of  the  lungs,  and  reaches  every  air-cell. 

315.  The  systemic  or  system  arteries,  is  the  name  ef 
those  which  lead  the  blood  into  every  part  of  the  body. 

Branches  of  them  supply  the  heart,  which  derives  no  more  benefit 
from  the  blood  it  contains  than  any  other  part  of  the  body,  the  blood 
not  nourishing  it  till  thrown  into  the  arteries,  in  some  small  branches  of 
which,  the  blood  meanders  through  the  heart,  and  nourishes  it.  No  more 
do  the  arteries  derive  any  selfish  benefit  from  the  labor  they  perform, 
in  respect  to  the  blood ;  they  are  not  allowed  to  "  toll  it,"  but  are  nourished 
by  a  set  of  small  vessels,  in  the  same  manner  as  other  parts  of  the  body. 
Some  branches  of  these  arteries  are  distributed  through  the  lungs,  which 
have  derived  no  peculiar  benefit  from  the  visitation  of  the  blood  from  the 
right  heart. 

316.  The  systemic  arteries  commence  at  the  top  of  the 
left  ventricle,  by  a  single  large  vessel,  the  grand  aorta,  which 
rises  up  nearly  to  the  top  of  the  breast-bone,  where  it  forms 
an  arch,  at  the  summit  of  which  it  allows  branches  to  pass 
fo  the  right  arm  and  the  right  side  of  the  head,  without  and 
within,  and  to  the  left  arm  and  left  side  of  the  head.     The 
"branches  passing  to  the  head  are  very  large,  and  allow  more 
Hood  to  pass  in  proportion  to  the  size  of  the  head,  than  exists  in 
any  other  part  of  the  body,  except  the  kidneys.     This  indi- 
cates the  importance  of  the  changes  which  take  place  in  the 
head,  or  which  should  take  place  in  the  head.    The  aorta  then 
follows  down  on  the  left  of  the  middle  of  the  back -bone,  giving 
off  branches  to  the  ribs,  large  branches  to  the  digestive  organs, 
especially  the  second  stomach,  and  to  the  kidneys. 

The  importance  of  the  action  of  these  organs  is  therefore  great. 


SEC.  2.]  THE  BLOODVESSELS.  343 

317.  Before  it  reaches  the  pelvis,  the  Aorta  divides  into 
two  grand  branches,  which  extend  into  the  lower  extremities. 
The  situation  of  the  main  artery  of  the  leg,  it  is  best  to  notice, 
as  whatever  stops  the  flow  of  blood  in  that,  checks  the  flow 
of  blood  from  any  injured  lower  division.  Coming  out  from 
the  abdomen,  the  artery  called  femoral  in  this  place,  imme- 
diately finds  its  way  to  the  midst  of  the  leg,  upon  the  inside 
of  the  thigh-bone.  Where  it  comes  out  from  the  abdomen 
o^er  the  hip-bone,  is  a  very  good  place  to  exert  pressure 
upon  it,  as  the  bone  is  directly  below,  and  allows  a  person  to 
exert  pressure  with  effect.  Its  direction  is  not  straight,  as  its 
object  is  to  get  behind  the  knee ;  its  course  may  be  known, 
however,  by  the  tailor's  muscle  (Lith.  PI.  1,  Fig.  1),  as  it  is 
directly  below  the  inner  edge  of  that  muscle  (Fig.  105). 

318.  The  firmness  of  the  artery,  and  the  large  amount  of  fleshy  sub- 
stance beneath  and  upon  which  it  is  imbedded,  renders  it  very  difficult  to 
comprtss  the  artery.     It  can  however  be  accomplished,  by  tying  a  knot  in 
a  handkerchief  or  any  strong  band,  and  by  putting  the  knot  over  the  edge 
of  the  tailor's  muscle,  the  ends  of  the  band  being  brought  to  the  opposite 
sideof  the  limb  and  tied  together  snugly,  but  with  a  little  length  of  bandage 
between  the  last  knot  and  limb,  that  a  stick,  iron,  or  any  handy  thing  may 
be  pit  under  and  twisted  round,  thus  forcing  the  first  knot  to  compress 
the  bloodvessels.     To  do  this  better,  something — a  few  pennies,  a  smooth 
stone,  or  bit  of  wood — may  be  placed  under  the  first  knot,  which  will  then 
press  all  the  more  forcibly.     If  the  knot  do  not  happen  to  be  over  the 
artery,  it  can  be  moved  a  little  to  one  side  or  the  other  ;  but  every  thing 
must  be  done  quickly. 

319.  The  situation  of  the  artery  of  the  arm  may  also  be 
noticed  (Fig.  106). 

Where  it  comes  over  the  first  rib  it  may  be  pressed  upon  with  the 
advantage  of  the  bone  beneath,  but  the  most  convenient  place  at  any 
time  is  found  in  the  arm,  in  which  the  main  artery  lies  deeply  buried. 
The  inner  edge  of  the  biceps  muscle,  so  easily  felt  on  the  front  part  of 
the  arm,  is  over  the  artery,  and  therefore  a  guide  to  its  situation.  It  may 
be  acted  on  in  the  same  manner  as  the  artery  of  the  legs.  If  the  blood- 
vessels of  the  head  bleed  badly,  it  is  easy  to  make  pressure  upon  them. 


344  THE  CIRCULATOKY  ORGANS.  [CHAP.  II, 

Tig.  105.  Fig.  106.       -t  i- 


Flg.  105.— 2, 2,  Divided  ends  of  "  tailor's  muscle."    1, 1,  Femoral  artery. 
Fig.  106.— Arm,  with  parts  removed  to  show  the  situation  of  the  main  artery. 

320.  The  arteries  which  enter  the  head  pass  through  a  canal  winding 
in  the  bone,  as  if  there  were  danger  to  be  apprehended  from  allowing 
the  blood  to  rush  with  great  force  to  that  grand  nervous  centre  contained 
in  the  skull. 

321.  There  is  one  thing   exceedingly   interesting,  and 
very    important,   in   respect   to    the    arteries.     They    are 


SEC.  2.]  THE  BLOODVESSELS.  345 

buried  deeply  below  the  surface  in  almost  all  parts  of  the 
body. 

The  object  of  this  is,  in  the  first  place,  to  protect  them  from  danger. 
This  is  so  important,  that  sometimes  the  arteries  are  seen  partly  or  wholly 
surrounded  by  a  long  bony  channel,  as  observable  in  the  under  edges 
of  the  ribs. 

322.  But  another  still  more  important  and  also  constant 
benefit  arises  from  this,  that  the  blood  in  the  arteries  is  kept 
warmer. 

When  it  is  considered  that  one  very  important  duty  fulfilled  by  the 
blood  is  to  convey  heat  to  parts  where  it  is  needed,  the  value  of  this 
arrangement  of  the  arteries  will  be  appreciated.  To  understand  this 
fully,  however,  a  few  general  remarks  must  be  made. 

323.  A  great  portion,  if  not  all  the  heat  of  the  body  is  produced  in 
the  central  organs ;  chiefly  or  wholly  in  the  lungs,  for  the  blood  is  not  so 
warm  when  it  enters  as  when  it  leaves  them.  It  is  found  by  experiment 
that  the  temperature  of  the  stomach  averages  about  100  degrees,  the 
heart  is  a  little  warmer.  The  throat  has  an  average  temperature  of  98, 
the  top  of  the  brain  96,  the  hands  94,  the  feet  92.  Now  one  of  the 
most  important  duties  to  be  fulfilled  in  the  protection  of  health,  is  to 
keep  the  various  parts  at  their  natural  healthful  temperatures.  The 
instant  any  part  rises  or  falls  in  temperature,  a  person  begins  to  lose 
health. 

324.  It  is  also  evident  that  any  part  will  be  kept  warm, 
all  other  things  being  equal,  in  ratio  with  the  quantity  of 
blood  it  receives  and  its  distance  from  the  heart. 

The  head,  therefore,  will  be  always  warm  enough,  as  the  blood 
has  but  a  short  distance  to  go,  and  flows  to  the  head  in  very  large  quan- 
tities. There  is,  therefore,  a  reason  for  the  old  proverb,  "  keep  the  head 
cool."  There  is  also  a  reason  why  the  head  should  perspire  sooner  than 
any  other  part  of  the  body,  viz.,  it  will  need  cooling  earliest.  There  is 
a  reason  why  the  head  should  not  be  covered  with  fur  caps,  &c.,  as  they 
keep  the  head  too  hot,  except  in  the  coldest  weather.  There  is  a  reason 
why  infants  should  not  have  caps  upon  their  heads.  There  is,  also,  a 
reason  why  the  face  does  not  need  a  covering  except  in  the  coldest 
weather,  viz.,  it  is  supplied  with  a  large  quantity  of  blood  directly  from 
the  heart.  There  is,  also,  a  reason  why  neckcloths,  &c.,  tend  to  produce 

15* 


346  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

sore  throat,  inflammation  there,  &c.,  and  why  the  custom  of  ladies  to 
leave  the  upper  part  of  the  neck  uncovered  is  more  advantageous  than 
the  fashion  of  men. 

325.  We  find  in  respect  to  the  throat  and  head,  that  nature  has  not 
buried  the  vessels  deeply  until  it  was  necessary  for  reaching  the  parts 
within  the  skull ;  for  the  arteries  leading  to  the  head  are  situated  near 
the  windpipe,  through  which  the  air  is  constantly  passing,  and  of  course 
cooling  the  blood  in  its  vicinity. 

326.  The  distance  to  the  hands  and  feet  is  great,  and  the 
quantity  of  blood  flowing  to  them  comparatively  small. 

The  arteries  *  are,  therefore,  buried  deeply,  that  the  blood  flowing 
through  them,  may  not  be  too  cool  before  it  reaches  its  destination.  For 
accomplishing  this  purpose  better,  a  deposit  of  fat  is  made  in  cold 
weather  ;  to  which  ingenuity  and  judgment  should  add  clothing,  as  need 
may  be. 

327.  It  cannot,  therefore,  be  said  with  any  propriety,  that 
a  child  by  "habit/'  is  "just  as  well  with  short  sleeves"  as 
long  ones. 

It  will  not  be  denied  by  any,  that  habit  would  do  something  toward 
lessening  the  evil  which  results  from  clothing  too  thinly — it  can,  how- 
ever, do  but  little.  If  the  hands,  arms,  and  feet  be  kept  perfectly  warm, 
that  is  sufficient ;  but  if  they  be  not,  either  the  quantity  of  blood  moving 
through  the  part  in  a  given  time  must  be  increased,  or  such  coverings 
worn  as  shall  prevent  the  blood  which  visits  the  part,  from  becoming 
cold  before  it  arrives  there. 

328.  Two  facts  are  worthy  of  notice,  before  leaving  the 
arteries.     In  the  first  place,  they  are  merely  channels  of 
Communication  from  the  heart  to  all  parts  of  the  body. 

The  blood  is  the  same  in  all  respects,  except  its  temperature,  when  it 
leaves  the  arteries  as  when  it  left  the  heart. 

329.  In  the  second  place,  the  blood  differs  in  tempera- 
ture, color,  and  quality  in  the  different  sets  of  arteries. 

It  is  not,  therefore,  the  character  of  its  contents  which  renders  it 
necessary  a  bloodvessel  should  be  an  artery.  But  if  the  blood  be  driven 


*  It  was,  therefore,  the  expression  of  an  ignorant  Indian 
as  we  are  told— that  he  was  "  all  face." 


,  who  said— 


SSC.  2.]  THE  BLOODVESSELS.  347 

by  the  heart  directly  into  a  vessel,  it  must  be  constructed  like  an  artery, 
to  wit,  it  must  be  an  artery. 

B.  Capillary  Bloodvessels. 

330.  The  capillary  (hair-like)  vessels  are  so  called  from 
being  very  small. 

How  their  walls  or  sides  are  formed,  or  what  particular  properties 
they  possess,  is  not  certainly  known  further  than  this — they  are  capable 
of  enlargement  and  diminution,  to  how  great  a  degree  compared  with 
their  ordinary  size,  is  not  known. 

331.  They  exist  in  the  form  of  a  network  (Lith.  PI.  3, 
Fig.  3),  where  it  is  seen  very  much  magnified.     This  net- 
work of  capillaries  exists  in  every  part  of  the  body. 

It  is  much  more  extensive  in  some  parts  than  in  others — that  is  to 
say,  the  vessels  and  the  meshes  of  the  network  are  naturally  larger  in 
some  parts  than  in  others. 

332.  The  blood  flows  from  the  arteries  into  the  capilla- 
ries, and  in  them  undergoes  all  its  changes,  except  in  tem- 
perature. 

That  is,  in  them  its  color  is  changed ;  through  them  the  parts  of  the 
body  are  nourished,  &c.  How  this  is  accomplished,  is  not  known. 
Some  suppose  that  the  part  of  the  body  requiring  any  thing  existing  in  the 
blood  passing  through  the  capillaries,  has  the  power  of  drawing  or  attract- 
ing it  through  the  sides  of  the  capillaries.  Some  suppose  that  the  capillary 
has  an  active  agency  in  all  such  operations.  How  far  also  from  the 
capillary  any  part  may  be  influenced  by  the  blood  of  the  capillary,  or 
exert  an  influence  upon  it,  is  conjectural.  The  distance  from  one  capil- 
lary to  another  is  not  great,  but  yet  it  is  something,  and  substance 
exists  there  ;  undergoing  frequent  changes,  and  it  must,  therefore,  pass  a 
short  distance  before  it  can  pass  into  the  capillary,  or  from  the  capillary 
to  its  needed  place.*  Hence  different  parts  will  be  nourished  with  dif- 
ferent degrees  of  rapidity ;  and  it  might  be  expected,  as  is  the  case,  that 
one  part  would  be  very  quick  and  another  very  slow  in  recovering — espe- 

*  Some  suppose,  that  substance  is  constantly  leaving  the  capillaries, 
and  traversing  more  or  less  slowly  the  spaces  between  them,  if  it  do 
not  happen  to  be  needed  on  the  way. 


348  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

cially  considering  one  thing  besides,  viz.,  that  some  parts,  when  injured, 
would  require  for  their  restoration  a  large  amount  of  substance,  which  is 
usually  found  in  the  bloodvessels  in  very  small  quantity. 

333.  Thus,  when  the  bones  are  broken  or  the  tendons  injured,  espe- 
cially after  the  body  is  mature,  they  will  be  very  slow  in  recovering ;  for 
as  they  do  not,  day  by  day,  require  to  undergo  very  rapid  changes,  the 
bloodvessels   in  them  are  not  very  numerous,  comparatively  speaking ; 
they  also  require  substance  comparatively  rare  in  the  blood.     Whoever, 
therefore,  has  a  broken  bone,  must  expect  it  will  be  useless  a  long  time. 

334.  Also  when  the  ligaments  are  sprained,  the  part  must  be  kept 
quiet  for  a  long  time,  that  the  healing  process  may  take  place.     For 
though  the  reason  of  it  cannot  be  given,  it  is  a  fact  that  substanc  e  newly 
formed,  is  not  as  perfectly  adapted  to  its  purpose  as  after  it  has  under- 
gone its  changes  many  times :  hence  the  muscles  of  the  rapidly-growing 
child  are  apt  to  allow  the  back  to  lean  ;  a  bone  newly  united  is  easily 
jroken  again ;  bones  dislocated  and  replaced,  are  thrown  out  of  place 
more  easily  a  second  time,  if  it  occur  within  a  short  period.     The  sub- 
stance which  forms  a  scar,  is  more  easily  affected  by  disease  than  proper 
flesh ;  and  the  more  recently  it  has  been  formed,  the  more  easily  is  it 
diseased.     A  slight  exertion  may,  therefore,  undo  all  that  nature  ha> 
done  in  effecting  a  cure. 

335.  It  is  also  worthy  of  notice,  that   if  the  capillary 
vessels  become  distended  with  blood,  they  cannot  perform 
their  duties  in  nourishing  or  otherwise  acting  upon  any  part. 

This  state  of  the  vessels  is  called  congestion,  when  the  blood  is  stag- 
nant, if  such  an  expression  may  be  used,  or  when  the  blood  moves  very 
slowly  ;  but  when  the  vessels  are  unnaturally  full  of  blood,  moving 
actively,  a  state  of  inflammation  exists. 

336.  When  any  part  is  to  be  restored  from  injury,  there- 
fore, two  things  are  to  be  kept  in  mind.     The  blood  must  not 
be  allowed  to  circulate  too  freely ;  and  on  the  other  hand, 
its  circulation  must  be  as  active  as  is  allowable. 

C.   The  Veins. 

337.  The  veins  commence  in  the  capillaries  of  every 
part  of  the  body,  and  lead  the  blood  back  to  the  right  heart, 
with  the  exception  of  the  veins  from  the  pancreas,  stomach, 


SEC.  2.]  THE  BLOODVESSELS.  349 

second  stomach,  and  spleen  (Lith.  PI.  4,  Fig.  4),  which  unite 
and  form  the  portal  vein  leading  into  the  liver,  and  one  class 
of  veins  which  (Lith.  PL  3,  Fig.  2)  lead  the  blood  from  the 
capillaries  about  the  air  cells  of  the  lungs  to  the  left  heart, 
(Lith.  PI.  4,  Fig.  2).* 

It  may  be  here  observed,  that  opening  from  the  capillaries  of  the  liver 
and  lungs  there  are  veins  which  lead  to  the  right  heart. 

338.  The  veins  have  three  coats.     The  outer  one  is  sim- 
ilar to  the  outer  coat  of  arteries,  but  is  not  as  firm.     The 
middle  coat  is  very  thin,  and  said  by  some  not  to  exist.    The 
inner  coat  is  like  that  of  the  arteries,  and  is  a  continuation  of 
the  lining  of  the  heart. 

When  the  veins  are  cut  across  they  do  not  remain  open,  like  an 
artery,  but  are  closed  with  slight  pressure.  When  they  have  been  cut, 
a  bandage  upon  the  wound  is  quite  sufficient,  especially  if  assisted  by  the 
application  of  cold. 

339.  As  the  veins  unite  with  each  other,  they  form  very 
obtuse  angles  as  a  general  thing,  as  seen  on  the  back  of  the 
hand  and  in  Fig.  107,  while  in  case  of  the  arteries  they  are 
joined  at  very  acute  angles.     Within  the  veins  are  found 
"folds"  of  the  inner  coat  (Fig.   108),   which  answer  the 
purpose  of  valves  to  prevent  the  blood  from  flowing  back. 

Fig.  107. 


The  position  of  these  in  the  veins  of  the  back  of  the  hand  will  be 
noticed  if  the  fingers  be  drawn  down  on  its  back,  a  little  in  front  of  the 

*  The  veins  of  the  portal  system  will  be  considered  in  connection 
with  the  excreting  organs,  and  the  veins  leading  from  the  lungs  to  the 
right  heart  will  be  considered  when  treating  on  the  lungs. 


350  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

Fig.  108. 


Fig.  108. — Vein  cut  open  to  show  valves,  a,  a,  above  which  the  pouching  parts,  bt 
6,  are  seen. 

fingers  small  "  lumps"  will  be  seen.  These  are  where  the  valves  resisting 
the  blood  cause  it  to  distend  the  veins.  A  little  above  the  finger,  from 
certain  points,  some  of  the  veins  will  appear  empty.  These  points  are, 
also,  the  places  of  valves  which  prevent  the  blood  from  flowing  into  the 
empty  veins. 

340.  These  valves  do  not  exist  in  the  head. 

As  it  was  the  intention  of  nature  that  the  head  of  man  should  be 
upright,  hence  the  head  should  not  be  held  "  down  "  long  at  a  time,  as 
the  blood  runs  back  into  the  head.  Children  should  not  turn  "  somersets," 
"  stand  on  the  head,"  nor  should  any  one  sleep  with  the  head  level  with 
the  body,  especially  if  he  be  subject  to  any  nervous  affections.  A  child 
should  not  be  placed  on  the  lap  or  carried  with  the  head  down.  The 
bed  for  the  child  should  be  made  upon  scientific  principles,  with  the  head 
the  highest,  the  trunk  the  lowest,  and  the  feet  intermediate.* 

341.  The  veins  anastomose  or  open  into  each  other,  very 
frequently,  and  are  of  two  kinds.     The  large  veins  situated 
directly  beneath  the  skin,  being  called  the  superficial  veins. 
The  others  being  called  deep  veins,  and  are  for  the  most  part 
found  in  company  with  the  arteries,  each  one  of  the  main 
arteries  being  accompanied  by  two  veins.     Thus  the  veins 
are  much  more  numerous  and  capacious  than  the  arteries  of 
the  body. 

*  There  is  as  much  art  in  making  a  bed  well,  as  in  making  good 
bread.  The  bed  should  be  level  from  side  to  side,  as  otherwise  there  is 
much  fatigue  produced  by  retaining  the  position  of  the  body  during  sleep, 
and  a  person  feels  in  the  morning  as  if  he  had  been  rolling  down  hill  all 
night.  If  the  foot  of  the  bed  be  a  little  too  low,  the  blood  has  difficulty 
in  finding  its  way  back  to  the  heart,  &c.,  &c. 


SEC.  2.]  THE  BLOODVESSELS.  351 

342.  All  the  veins  from  the  upper  parts  of  the  body,  at 
last  unite,  and  form  one  (Lith.  PI.  4,  Fig.  1),  called  the  de- 
scending vena  cava.  All  those  from  the  lower  parts  of  the 
body,  unite  to  form  one  (Lith.  PI.  4,  Fig.  1),  called  the  as- 
cending vena  cava.  The  venae  cavse  terminate  or  open  into 
the  right  auricle. 


D.     The  Lymphatics. 

343.  Lymphatics  is  the  name  given  to  a  class  of  vessels  which  exist 
in  many  parts  of  the  body.     The  name  is  given  on  account  of  the  pellucid 
fluid  called  lymph,  which  is  found  in  them. 

344.  The  largest  of  them  are  very  small,  and  they  all  have  much 
the  appearance  of  a  string  of  small  beads  (Fig.  109),  which  is  produced 
by  their  valves,  something  like  those  of  the  veins,  which  are  very  numer- 
ous, and  formed  of  folds  of  the  inner  coat  of  the  lymphatic,  which 
"  pouches"  between  the  valves. 

Fig.  109. 


«f 

=3C 

Fig.  109.— Lymphatic  vessels,  one  being  cut  open  to  show  the  valves  a,  a. 

345.  How  the  lymphatics  commence, is  not  well  determined.     When 
first  plainly  seen,  they  appear  in  the  form  of  a  network,  which  some  be- 
lieve to  communicate  with  the  capillaries,  but  which  others  think  com- 
mence independently  of  any  other  vessels. 

346.  The  proper  lymphatic  vessels  commence    from    this  network. 
They  are  composed  of  two  coats,  the  inner  one  of  which  is  formed  into 
folds,  as  said.     Their  course  is  nearly  parallel,  and  throughout  the  whole 
of  it,  they  increase  but  little  in  size.     Their  course  is  nearly  in  a  direct 
line  from  their  commencement  to  their  destination,  viz.,  the  bloodvessels 
at  the  root  of  the  neck. 


352  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

347.  They  communicate  with  each  other,  but  not  as  frequently  as  the 
veins  or  arteries,  and  by  branches  no  smaller  than  the  main  trunks,  from 
which  they  pass,  or  which  they  form. 

348.  In  their  course  are  situated  softish  bodies,  called  glands,  half  or 
two-thirds  the  size  of  a  kernel  of  corn.     Some  are  larger,  others  smaller. 
They  are  very  fully  supplied  with  bloodvessels.     The  vessels  which  enter 
these  glands  are  more  numerous  and  a  trifle  smaller  than  those  which 
leave  them  (Fig.  98). 

349.  The  lymphatics  and  their  glands  are  of  three  kinds.     The  su- 
perficial are  found  immediately  below  the  surface  of  the  skin.     The 
deep  are  found  following  the  course  of  the  deep  veins.     The  lacteals, 
heretofore  described,  are  considered  as  a  third  class  of  lymphatics,  as  their 
structure  is  similar,  though  the  office  of  the  lacteals  is  well  known,  but 
that  of  the  lymphatics  not. 

350.  Some  suppose  that  many  of  the  small  lymphatics  terminate  in 
the  roots  of  the  veins,  and  that  branches  of  the  lymphatics  open  into  the 
larger  veins  ;  but  this  probably  is  not  correct.     The  lymphatics  from  the 
lower  part  of  the  body  find  their  way  to  the  thoracic  duct,  which  opens 
into  the  veins  of  the  neck,  on  the  left  side  ;  at  the  same  point  also,  termi- 
nate the  lymphatics  from  the  left  side  of  the  head,  left  arm,  and  left  side 
of  the  chest ;  while  the  lymphatics  of  the  right  side  of  the  head,  right  arm, 
and  right  side  of  the  chest,  terminate  at  a  point  of  the  neck-veins  on  the 
right  side,  corresponding  to  the  termination  of  the  thoracic  duct. 

351.  The  fluid  found  in  the  lymphatics  is  very  similar  to  the  serum 
of  the  blood  in  general  appearance.     They  are  sometimes  filled  with  it, 
and  sometimes  nearly  empty. 

352.  The  arrangement  of  the  valves  signifies  which  way  the  lymph 
moves.     The  force  which  moves  it  is  thought  by  some  to  exist  in  the 
lymfhatics  themselves,  by  others  to  be  derived  in  part  from  the  capillary 
bloodvessels,  and,  perhaps,  even  the  heart  acting  through  them.     Others 
think  the  manner  in  which  the  lymphatics  open  into  the  veins  draws  the 
lymph  on  into  the  bloodvessels ;  but  the  only,  as  yet,  certain  force  is 
found  in  the  pressure  of  the  contracting  muscles,  and  rubbing  the  system. 
How  much  importance  is  to  be  attributed  to  the  circulation  of  the  lymph,  is 
not  known  ;  but  it  is  worth  while  to  notice  the  advantage  of  exercise  and 
rubbing,  in  increasing  the  rapidity  of  the  motions  of  the  lymph. 

353.  The  utility  of  the  lymphatics  is  not  known.     Some  suppose  they 
absorb  all  the  waste  substance  that  is  produced  by  the  wear  of  the  sys- 
tem.    But  as  no  lymphatics  have  been  found  in  the  nervous  substance,  in 
the  bones,  cartilages,  muscles,  or  tendons,  this  view  is,  without  doubt,  in- 


SEC.  3.]  CAUSES  OF  THE  CIRCULATION.  358 

correct.  Others  think  that  the  lymphatics  are  merely  for  the  purpose 
of  taking  up  fluid  substance  which  is  not  of  use  in  any  part  of  the 
body ;  but  the  above  objection  would  apply  to  shis  view.  Others  again 
think  that  the  lymphatics  take  up  all  substance  which  passes  into  the 
body  from  without,  either  through  the  stomach,  the  lungs,  or  the  skin  ; 
but  there  are  objections  to  this  view.  Our  minds  must  therefore  remain 
in  that  unsatisfactory  state,  which  is  very  disagreeable,  but  yet  most  pro- 
fitable, if  sufficient  facts  are  not  known  to  establish  any  point. 

354.  When  colds  are  taken,  the  lymphatic  glands  are  very  apt  to  be 
affected — to  swell  and  become  hard,  forming  "  kernels  "  in  the  neck  and 
elsewhere  ;  this  is  the  case  more  particularly  with  persons  of  a  "  con- 
sumptive constitution."  Why  it  should  be  so,  cannot  be  told.  When 
certain  parts  are  injured  or  diseased  in  peculiar  ways,  inflammation  is 
very  apt  to  extend  in  the  course  of  a  lymphatic  vessel,  perhaps  affecting 
but  one  of  them,  but  extending  in  it  very  rapidly.  The  particular  reason 
for  this  cannot  be  given. 


SECTION  3. — Causes  of  the  Circulation. 

355.  The  contractions  of  the  heart  are  the  most  power- 
ful  causes  which  distribute  the  blood  through  the  body. 

As  these  are  affected  by  the  emotions  and  various  states  of  the  dis- 
position, and  as  otherwise  it  beats  with  increased  or  diminished  rapidity, 
as  the  wants  of  the  system  require,  it  follows  that 

356.  The  action  of  the  mind  and  organic  nervous  sys- 
tem, and  of  course  the  state  of  the  general  health,  have  a 
powerful  influence  upon  the  circulation. 

Hence  the  physician  feels  the  pulse,  to  learn  the  condition  of  his  pa- 
tient. 

357.  The  arteries  dilating,  receive  the  blood  from  the 
contracting  heart,  and  reacting  upon  the  blood  when  the  heart 
dilates  or  relaxes,  they  force  the  blood  backward  against  the 
semi-lunar  valves — closing  them,  by  which  the  whole  pres- 
sure of  the  arteries  urges  the  blood  to  their  extremities. 

Some  suppose  the  arteries  contract  and  relax  alternately  with  the 


354 


THE  CIRCULATORY  ORJANS. 
Fig.  109  (B). 


[CHAP.  ii. 


Fig.  109  (B).— 1, 2, 3,  Aorta.  4,  5,  6,  Arteries,  branching  from  the  aorta.  7,  8,  9, 
Veins.  10, 11,  Certain  veins,  called  venae  azygos.  12,  Enlargement  of  the  thoracic 
duct,  called  the  receptaculum  chyli.  13, 14,  Thoracic  duct.  At  14,  a  lymphatic  vessel 
is  seen  opening  into  the  thoracic  duct.  15,  Lymphatic  of  the  right  side.  A,  Lacteals 
commencing  from  the  second  stomach.  B,  A  portion  of  lymphatics  from  the  lower 
parts  of  the  body. 


SEC.  3.]  CAUSES  OF  THE  CIRCULATION.  355 

heart.     Others  suppose  that  the  action  of  the  arteries  is  wholly  depen- 
dent upon  what  is  called  the  elasticity  of  the  arteries.     In  either  case 

358.  What  may  be  called  the  life  of  the  arteries  will  de- 
pend upon  the  state  of  the  nerves,  and 

Consequently,  the  circulation  through  the  arterup  is  influenced  by  the 
general  health.  Some  also  think  the  arteries  can  be  increased  or  dimin- 
ished in  size,  as  need  may  be,  under  the  action  of  the  nervous  influence. 
This  may  be  the  case  with  the  minute  arteries,  but  probably  not  with  the 
large  ones.  Disease  will  however  cause  enlargement  of  both  large  and 
small. 

359.  Every  cause  of  pressure  will  cause  the  blood  to 
flow  on,  toward  the  extremities  of  the  arteries. 

Hence  exercise  of  the  muscles  and  rubbing  the  system  increases  the 
rapidity  of  the  circulation. 

360.  It  is  however  essential  that  pressure  be  made  at  in- 
tervals, that  the  blood  may  flow  into  the  vessel  from  which  it 
has  been  pressed. 

Hence  tight  clothing  is  very  injurious,  by  exerting  constant  pressure. 

361.  The  arteries  branch  at  acute  angles  (Fig.  106  and 
Lith.  PL  4,  Fig.  1) ; 

Except  those  arising  from  the  arch  of  the  aorta,  in  which  the  course 
of  the  blood  is  such  that  it  leaves  the  aorta  more  easily  with  the  present 
arrangement. 

362.  The  area  of  two  branches  is  greater  than  that  of  the 
dividing  artery,  on  account  of  which  the  blood  flows  out  more 
readily,  as  explained  by  Fig.  110. 

363.  The  blood  is  also  drawn  onward  through  the  arte- 
ries by  the  passage  of  the  blood  through  the  veins. 

364.  Cold  tends  to  contract  the  arteries. 

If  it  be  applied  transiently,  however,  the  nervous  system  will  exert  a 
counteracting  influence. 

365.  The  efficiency  of  the  nervous  system  in  this  respect 
will  depend  upon  the  health  of  the  person,  and  upon  the  ex- 
tent of  the  action  of  the  cold. 


356  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

Fig.  110. 


Fig.  110. — B,  represents  a  fountain,  the  water  of  which,  by  its  pressure,  rushes  out 
with  greater  force,  on  account  of  the  increasing  size  of  A. 

If  a  person  be  exceedingly  feeble,  the  cold  will  conquer  from  the  first, 
if  it  act  but  upon  a  slight  extent  of  surface  ;  and  from  this  to  a  perfectly 
strong  and  healthy  constitution  successfully  opposing  cold  for  hours,  there 
will  be  all  grades  of  nervous  power. 

306.  Cold,  transiently  applied,  is  therefore  excellent  to 
arouse  and  increase  the  circulation  of  any  part,  if  the  health  be 
sufficient. 

367.  Cold,  continuously  applied,  will  always  overcome  the 
nervous  energies  in  time. 

Hence  cold  is  excellent  to  apply  when  the  vessels  of  any  part  are  in- 
jured and  bleeding,  and  when  also  it  is  desirable  to  check  the  too  active 
circulation  of  blood.  It  must  be  applied  continuously. 

368.  Heat  and  warmth,  on  the  other  hand,  increase  and 
relax  the  size  of  the  bloodvessels. 

Heat  is,  therefore,  excellent  to  increase  the  flow  of  blood  to  any  part, 
as  may  be  seen  by  wiping  a  wound  at  any  time  with  warm  applications. 

369.  Heat  applied  for  a  great  length  of  time,  enfeebles 
the  energies  of  the  bloodvessels. 

370.  Many  medicines  and  applications,  as  also  many  diseases,  either 
enlarge  or  diminish  the  size  of  the  arteries  either  directly  or  indirectly, 
through  the  nervous  system. 

371.  It  is  self-evident,  yet  worthy  of  remark,  that  if 
blood  be  in  one  part  it  cannot  be  in  another  part  at  the  same 


SEC.  3.]  CAUSES  OF  THE  CIRCULATION.  357 

time ;  and  also  that  there  is  a  given  amount  of  blood  in  the 
system  at  any  one  time. 

If,  therefore,  blood  circulate  too  actively  in  any  part,  it  may  be 
diminished  by  applications  to  the  part  which  will  lessen  the  circulation 
there  ;  or  applications  can  be  made  to  some  other  part  to  increase  the 
circulation  there,  which  must  have  a  tendency  to  diminish  the  circula- 
tion in  the  first  part — or  both  things  may  be  done  at  the  same  time. 
Also  the  quantity  of  blood  may  be  lessened  by  blood-letting. 

372.  Thus,  physicians  sometimes  apply  cold  to  diminish  the  circula- 
tion— as  when  a  person  has  been  intoxicated,  it  is  usual  to  pump  cold 
water  on  the  head. 

373.  In  case  of  apoplexy  and  various  fits,  physicians  will  rub  the 
body  every  where,  and  make  hot  applications  to  the  feet  and  hands. 

374.  In  case  of  croup,  warm  applications  are  made  to  the  feet ;  and 
cold  cloths  or  the  like,  to  the  throat. 

375.  In  case  of  inflammation  of  the  lungs  and  many  other  parts, 
physicians  are  in  the  habit  of  applying  blisters,  mustard  poultices,  &o., 
or  blood-letting,  either  with  the  lancet,  or  by  leeches.     It  must  be  re- 
membered, however,  that  other  purposes  are  frequently  served  by  blood- 
letting. 

376.  As  a  general  rule,  if  the  system  be  not  very  feeble, 
it  is  advisable  to  make  use  of  both  classes  of  applications  at 
the  same  time,  viz.,   applications  which  shall  diminish  the 
circulation  of  the  affected  part,  and  other  applications  to  other 
parts  which  will  increase  the  circulation  there. 

And  as  the  bloodvessels  are  smaller  the  nearer  we  approach  to- 
wards the  surface,  and  as  there  are  many  causes  which  retard  the 
circulation  of  the  blood  before  it  has  reached  the  extremities  of  the 
arteries,  and  also  because  the  surface  of  the  body  is  continually  exposed 
U  the  cold,  on  account  of  which  the  bloodvessels  are  liable  to  be  con- 
tracted, if  but  a  little, 

377.  It  is  exceedingly  important  that  when  there  is  any 
derangement  of  the  circulatory  system,  the  skin  be  rubbed 
very  briskly,  kept  warm,  &c.,  as  the  great  difficulty  will  be 
found  in  keeping  the  circulation  active  near  the  surface, 
and  preventing  the  accumulation,  of  blood  in  the  internal 
organs. 


358  THE  CIRCULATORY  ORGANS.  [CHAP.  II. 

And  as  the  action  of  the  circulatory  system  is  so  much  dependent  on 
the  nervous  system, 

378.  When  a  person  is  sick,  care  should  be  taken  to 
keep  the  circulation  active  in  the  skin  by  daily  rubbing, 
brushing,  &c. 

It  will  also  be  evident  that, 

379.  The  circulation  will  be  easily  deranged  when  the 
system  is  exhausted. 

Hence  why  people  take  cold  more  easily  in  the  evening  when  e.t- 
hausted  by  the  day's  labor,  than  in  the  morning  when  refreshed  by  sleep. 
Indeed,  cold  will  many  times  be  taken  from  exhaustion  alone,  or  inflam- 
mation may  be  produced,  as  the  system  becomes  too  feeble  to  preserve 
an  equal  circulation  in  every  part  of  the  body.  At  least,  when  the 
system  is  exhausted,  cold  will  produce  a  worse  effect  than  otherwise  ; 
but  if  the  system  be  warm,  exposure  to  cold  will  not  produce  so 
speedy  an  effect  as  if  the  system  be  exhausted  and  also  cold.  A  person 
never  takes  cold,  therefore,  because  he  is  warm,  but  because  exhausted. 
Usually,  however,  the  causes  which  have  produced  the  heat  have  ex- 
hausted the  system  ;  and  as  the  warmth  of  the  body  is  most  conspicuous, 
the  evil  suffered  is  attributed  to  the  system  being  too  warm.  A  person, 
if  warm  and  not  exhausted,  or  if  exhausted,  will  not  be  as  likely,  there- 
fore, to  take  cold  as  if  he  were  not  warm.  It  not  being  the  transition 
from  hot  to  cold  or  cold  to  hot,  which  produces  a  bad  effect,  but  the 
incapability  of  the  system  to  counteract  the  evil.  Taking  a  vapor  bath, 
if  not  to  the  point  of  exhaustion,  is  not  harmful,  nor  can  a  person  take 
cold  as  easily  after.  To  take  a  cold  bath  is  never  injurious  if  the  system 
be  vigorous,  and  not  exhausted. 

Causes  of  Circulation  through  the  Capillaries. 

380.  The  force  of  the  heart  and  of  the  arteries,  if  these 
last  exert  any,  is  not  expended  till  the  blood  passes  beyond 
the  arteries. 

381.  The  blood  is  also  drawn  on  by  the  movement  of  the 
blood  in  the  veins. 

Some  think  the  capillaries  exert  a  force  by  alternate  contraction  and 
relaxation,  like  a  great  multitude  of  hearts  beating  slowly.  Some  think 


SEC.  2.]  CAUSES  OF  THE  CIRCULATION.  359 

that  the  action  of  the  capillaries  is  owing  to  their  elasticity.      However 
this  may  be, 

382.  The  size  of  the  capillaries  is  most  evidently  under 
the  influence  of  the  mind,  the -nervous  system  of  organic 
life,  and  of  course,  the  general  health  of  the  whole  system. 

This  is  proved  by  the  paleness  and  flush  of  the  skin  varying  with 
every  sudden  emotion  of  the  mind.  By  the  rich  healthy  crimson  which 
overspreads  the  robust  cheek  when  presented  to  the  northwest  blast,  and 
by  the  pallor  of  general  debility,  as  common  expressions  prove,  for  we 
daily  hear  "  the  flush  of  health,"  "  sickly  looks,"  &c.  All  this  being 
produced  by  an  increased  or  diminished  size  of  the  capillary  bloodvessels 
of  the  part  considered. 

383.  All  the  remarks  made  upon  the  arteries,  apply  with  tenfold 
force  and  importance  to  the  capillaries,  and  they  need  not  be  repeated, 
but  should  be  re-read. 

Causes  of  Circulation  through  the  Veins. 

384.  The  blood  in  the  veins  is  doubtless  urged  on  by 
some  force  received  through  the  capillaries,  and  on  account 
of  their  valves,   are  singularly  benefited  by  exercise  and 
rubbing. 

Rubbing  should  be  used  with  little  force  against  the  valves,  as  they 
are  thin. 

385.  The  position  of  the  body  also  assists  the  return  of 
the  blood  through  the  veins. 

When  a  person  has  been  standing  much  on  the  feet,  the  blood  is  apt 
to  force  its  way  back,  through  the  valves,  distending  the  veins,  &c.  This 
is  remedied  by  bandaging  the  parts  liable  to  injury,  but  not  so  tightly  as 
to  check  the  flow  of  blood  through  the  deep  arteries.  Placing  the 
feet  in  an  elevated  position  will  facilitate  the  return  of  the  blood.  Hence 
those  who  stand  much  on  their  feet,  are  very  apt  to  throw  the  feet 
upon  the  table,  window,  stool,  &c.,  as  soon  as  opportunity  offers. 

386.  In  this  connection  it  may  also  be  mentioned,  that  if  it  be  not 
desirable  to  have  the  blood  circulate  through  any  part,  for  instance,  if  any 
part  be  wounded,  or  inflamed,  it  should  always  be  elevated,  as  then  the 
blood  flows  to  it  with  greater  difficulty,  while  it  flows  away  with  greater 


360 


THE  CIRCULATORY  ORGANS. 


[CHAP.  ii. 


387.  The  veins  of  the  head  are  not  furnished  with  valves. 
Hence  it  is  the  evident  intention  of  nature  that  the  head  should  be 

supported  above  the  heart,  otherwise  the  blood  "  settles"  back  into  the 
head.  Particular  care  should  be  taken,  to  have  the  head  elevated  during 
sleep,  in  case  of  children,  those  subject  to  fits,  convulsions,  apoplexy,  stu- 
dents, and  all  those  subject  to  irregularities  of  the  nervous  system.* 

388.  The  blood  is  also  drawn  through  the  veins  by  the 
"suction"  of  the  heart  and  inspiration  of  the  chest,  though  the 
amount  of  force  exerted  is  uncertain. 

389.  The  veins  as  seen  in  the  hand,  open  into  each  other 
almost  at  right  angles  (Fig.  107,  Lith.   PI.  4,  Fig.   1),  by 
which  the  blood  is  moved  on  with  greater  rapidity,  as  illus- 
trated by  Fig.  111. 

Fig.  ill. 


Fig.  111.— A,  C,  a  tube,  through  which  the  fluid  passes  from  the  small  towards  the 
large  extremity,  drawing  the  water  up  from  the  bowl  B,  through  the  tube  opening  at 
right  angles  into  A,  C. 


Conclusion. 

390.  By  all  these  causes,  the  blood  is  moved  through  the  system,  with 
almost  incredible  velocity,  and  without  the  slightest  jar  or  disturbance. 

*  As    before   shown,   there   is   no   danger   of   a   person   becoming 
-  crooked." 


CONCLUSION.  3(51 

Indeed,  the  movement  of  the  blood  takes  place  with  such  quietness,  that 
almost  every  one  overlooks  the  wonderful  action  constantly  going  on  in  hia 
system.  If  the  amount  of  blood  in  the  system  be  computed  as  20  pounds, 
it  will  be  between  the  extremes  of  eight  and  forty  pounds,  which  different 
persons  have  taken,  as  the  amount,  without,  however,  any  sure  means  of 
knowing.  It  has  been  shown,  that  at  least  four  pounds  per  minute,  is 
thrown  out  by  each  heart.  In  five  minutes,  therefore,  an  amount  equal 
to  all  the  blood  in  the  body,  will  be  thrown  out  by  the  hearts.  But  all 
the  blood  in  the  system,  is  not  in  active  motion.  If  a  frog's  foot  be  ex- 
amined under  a  microscope,  the  blood  will  be  seen  motionless  in  some 
vessels,  while  in  neighboring  ones,  its  motion  is  almost  as  quick  as  light- 
ning. 

If  it  be  computed,  therefore,  that  one-fifth  of  the  blood  in  the  body, 
viz.,  four  pounds,  is  in  active  circulation,  it  will  be  sufficient,  and  it  will 
follow,  that  in  one  moment's  time,  the  blood  can  run  through  the  entire 
circulation.  This  is  not  merely  speculative  ;  experiments  have  been 
tried  upon  horses.  A  substance  called  ferrocyanite  of  potash,  which  is 
veiy  easily  detected  in  blood,  was  injected  into  the  jugular  vein  of  the 
right  side  of  the  neck,  and  an  opening  made  in  the  Saphena  (great  vein 
of  the  hind  leg)  vein,  and  the  flowing  blood  caught  in  different  bowls, 
every  five  seconds.  In  the  fourth  bowl,  the  ferrocyanite  of  potash  was 
discovered.  That  is  to  say  in  less  than  twenty  seconds,  the  blood  hatl 
passed  down  to  the  right  heart,  thence  to  the  lungs,  back  to  the  left 
heart,  then  down  as  far  as  the  knee,  perhaps  the  foot  of  the  horse,  before 
it  turned  back  into  the  veins,  to  make  its  exit.  Other  similar  experiment* 
prove  conclusively,  that  one  minute  is  not  required  for  the  blood  to  cir- 
culate through  the  entire  system.  Hence  the  perfection  of  the  system  ; 
for  the  blood  almost  flies  round  and  round  in  its  rapid  circuit,  distribut- 
ing its  riches  to  every  needy  part,  equalizing  the  temperature,  by  wann- 
ing those  parts  which  are  cool,  and  cooling  those  parts  which  are  warm, 
instantly  removing  any  waste  substance,  and  transporting  it  where  it 
shall  be  cast  from  the  body,  in  one  form  or  another.  Were  a  volume  to 
be  filled,  the  wonderful  action  and  effects  of  the  circulatory  system,  could 
not  be  told. 


CHAPTER  III. 


THE   KESPIBATOBY    ORGANS. 


391.  It  has  been  clearly  shown,  that  the  food  taken  into  the  svstem  is 
in  part  composed  of  the  same  ingredients,  as  various  articles,  which  every 
experience  proves,  are  capable,  under  proper  circumstances,  of  producing 
heat.     One  of  the  most  important  of  these  circumstances,  is,  the  pres- 
ence of  pure  air.     A  candle  would  not  burn  in  the  stomach  or  blood- 
vessels, and  the  most  intensely  burning  fire  depends  upon  a  draught  of 
air,  and  goes  out  as  soon  as  entirely  deprived  of  it. 

392.  The  greater  the  quantity  of  air,  and  the  more  forcibly  it  is 
brought  in  contact  with  burning  substances,  the  more  rapidly  do  they 
burn,  and  the  more  heat  do  they  produce.     Since,  then,  the  production 
of  heat  depends  on  the  action  of  the  nir  upon  the  heat-producing  object, 
the  blood  must  be  acted  upon  by  the  air  ;  and  from  what  is  known  of 
other  things,  it  might  be  inferred,  that  the  greater  the  quantity  of  air 
acting  on  the  blood,  the  greater  the  amount  of  heat  produced. 

393.  The  respiratory,  or  breathing  apparatus  is,  there- 
fore, required  for  the  purpose  of  exposing  the  blood  to  the 
action  of  the  air. 

Its  great  utility  may  be  judged  from  the  fact,  that  the  blood  is  sub- 
ject to  the  action  of  the  air  in  the  lungs,  at  each  circulation.  That 
the  action  of  the  air  upon  the  blood  is  like  its  action  upon  other  substances 
when  they  produce  heat,  may  be  inferred  from  the  fact,  that  the  blood 
returning  from  the  lungs  to  the  left  heart,  is  warmer  than  the  blood  en- 
tering the  lungs. 

394.  Three  classes  of  organs  are  necessary  to  accomplish 
the  desired  object.     1st.  An  apparatus  to  receive  the  air. 
£d.  An  arrangement  of  organ*  for  circulating  the  blood  in 


SEC.  1.]  THE  AIR  PASSAGES.  303 

such  a  manner,  that  it  shall  be  extensively  acted  upon  by  the 
air.     3d.  An  apparatus  for  removing  and  replacing  the  air, 
the  good  qualities  of  which,  have  been  exhausted  by  use. 
There  are,  therefore  to  be  four  sections  in  this  chapter. 


SECTION  1. — The  Air  Passages. 

395.  On  its  way  to  act  on  the  blood,  the  air  naturally 
enters  the  nose  first.     This  has  been  prepared  for  warming 
it  before  it  enters  the  more  sensitive  windpipe. 

Hence,  one  reason  why  the  passage  is  narrowed  by  the  turbinated 
bones,  and  the  contraction  of  the  muscles,  which  partially  close  the 
opening  into  the  nostrils.  Hence,  also,  the  reason  why  diseases  of  the 
lining  of  the  windpipe  and  the  nose,  are  so  similar ;  for  as  they  were  in- 
tended to  serve  the  same  purpose,  viz.,  the  passage  of  the  air,  they  have 
been  constituted  in  the  same  manner ;  whether  their  diseases  are  simi- 
lar on  this  account,  or  because  similar  nervous  influences  are  exerted 
upon  each,  is  not  known. 

396.  The  throat  is  a  passage,  common  to  the  air  passing 
through  the  nose  or  mouth ;  an  opening  from  it  leads  into 
the  upper  and  back  part  of  the  windpipe.     This  opening  is 
closed  by  raising  the  windpipe,  till  the  edges  of  its  opening 
are  brought  against  what  is  called  a  valve,  or  the  epiglottis. 
It  is  a  piece  of  cartilage,  shaped  like  a  leaf.     It  is  connected 
by  one  end  to  the  inner  and  upper  edge  of  the  front  of  the 
windpipe.     Its  upper  surface,  for  two-thirds  of  the  way,  is  at- 
tached to  the  under  part  of  the  back  portion  of  the  tongue. 
The  remaining  portion  projects  into  the  throat,  in  an  upward 
and  backward  direction,  and  is  easily  felt  by  passing  the 
finger  over  the  tongue. 

397.  The  windpipe  is  composed  of  three  parts.      The 
first,  called  the  larynx,  the  large  part  in  the  upper  and  front 
region   of  the   neck,  called,  sometimes,  Adam's  apple.     I{ 


364  THEE  RESPIRATORY  ORGANS.  [CHAP.  III. 

appears  large,  externally,  but  from  its  structure,  (hereafter  to 
be  considered,)  its  passage  is  quite  narrow. 

398.  The  second  part,  called  the  trachea,  is  a  straight  tube, 
two  thirds  of  its  circumference  formed  of  cartilaginous  hoops, 
closed  behind  by  membrane.     The  rings  are  connected  with 
each  other  by  elastic  yellow  membrane.    The  trachea  reaches 
from  the  larynx  to  a  little  below  the  upper  part  of  the  breast- 
bone, where  it  divides,  to  form 

399.  The  third   part,  called   the  bronchii.      They   are 
merely  the  divisions  of  the  trachea,  and  formed  like  it.    They 
are   found  in  the   chest,   upon   either  side  of    the  centre 
(Fig.  112). 

Fig.  112. 


Fig.  112.— L,  Larynx.    T,  Trachea.    D,  Bronchii.    L,  L,  Left  lung. 

A  good  idea  will  be  formed  of  them,  if  the  leaves  be  stripped  and 
the  wood  removed  from  the  bark  of  a  tree.  The  hollow  bark  would 
represent  the  windpipe. 

400.  The  entire  length  of  the  windpipe,  commencing  at 


SEC.  2.]  CIRCULATION  OF  THE  BLOOD.  365 

the  throat,  is  lined  by  a  very  delicate  membrane,  called 
mucous  membrane.  When  it  arrives  at  the  smallest  divisions 
of  the  windpipe,  it  is  most  beautiful.  At  the  extremities  of 
these  divisions,  it  is  formed  into  little  pouches,  cells,  vesicles, 
or  sacs  (Lith.  PL  3,  Fig.  2).  The  largest  of  these  are  not 
larger  than  a  mustard-seed ;  but  they  are  so  numerous,  that 
one  author  has  computed  there  are  not  less  than  180,000,000 
in  the  lungs  of  one  person. 

401.  These  are  the  receptacles  of  the  air.  Into  these  it  is  drawn, 
and  from  these  it  is  thrown  out.  The  entire  arrangement  is  for  the  pur- 
pose of  causing  the  air  to  act  on  a  great  extent  of  surface,  and  if  the  sur- 
face of  so  many  millions  of  cells  be  computed,  it  will  not  probably  fall 
short  of  that  so  frequently  made,  viz.,  that  there  is  more  surface  in  the  air 
passages  than  upon  the  whole  body.  The  added  capacity  of  so  many 
cells  must  be  comparatively  very  great,  and  the  cells,  taken  as  a  whole, 
will  occupy  much  more  room  when  full  than  when  empty. 


SECTION  2. — Circulation  of  the  Blood  about  the  Air  Passages. 

402.  There  are  two  circulations.  One,  the  grand  circulation  usually 
spoken  of,  the  purpose  of  which  is  to  bring  the  blood  just  returned  from 
the  body,  in  contiguity  with  the  air.  The  other  is  for  the  purpose  of 
nourishing,  &c.,  the  air-tubes,  bloodvessels,  &c. ;  and  is  produced  by  the 
action  of  the  left  heart,  which  sends  the  life-giving  blood  to  all  parts  of 
the  body. 

403.  It  has  been  seen,  that  the  blood  coming  into  the 
right  heart  from  all  parts  of  the  body,  is  thrown  out  through 
a  vessel  which  immediately  divides;  one  branch  accompany- 
ing the  windpipe  on  one  side,  the  other  branch  passing  to 
the  other  division  of  the  windpipe. 

404.  As  often  as  the  windpipe  divides  (Lith.  PL  3,  Fig.  2) 
the  bloodvessel  accompanying  it  divides  in  a  similar  manner, 
till  at  last  the  minute  divisions  of  the  bloodvessels  reach  the 
air-cells,  when  they  pour  their  contents  into  the  capillary 


366  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

bloodvessels  which  form  upon  the  sides  of  the  air-cells  a 
most  beautiful  network  (Lith.  PL  3,  Fig.  3). 

405.  From  this  network,  the  blood  passes  into  the  veins 
to  return  to  the  left  heart.  They  accompany  the  divisions 
of  the  windpipe,  uniting  at  the  junction  of  the  branches  of  the 
windpipe — two  veins,  however,  being  found  by  the  side  of 
each  branch,  and  two  veins  from  each  side  returning  to  the 
left  heart. 


SECTION  3. — Inhalation  and  Exhalation  of  Air. 

406.  The  air-cells  are  filled  upon  the  principle  that  gra- 
vitation causes  air  to  rush  into  any  cavity  (Fig.  113). 

Fig.  113. 


Fig.  113.— C,  C,  represents  the  sides  of  the  chest.  D,  the  diaphragm.  T,  trachea. 
L,  lung.  D  is  never  in  reality  drawn  down  as  far  as  the  dotted  line  below ;  but  if  it 
were,  and  as  far  as  it  moved,  it  would  tend  to  produce  a  vacuum  if  the  air  were  not 
pressed  down  through  the  mouth  and  into  the  bag  L,  which  is  distended  to  the  dotted 
line/ 

407.  The  air-cells  are  situated  in  each  side  of  the  chest, 
and  communicate  with  the  air  through  the  windpipe  and 
nose,  or  mouth. 

408.  The  chest  is  composed  of  the  back-bone,  the  ribs 


SEC.  3.]     INHALATION  AND  EXHALATION  OF  AIR.        367 

and  their  cartilages,  and  the  breast-bone  as  a  framework 
(Figs.  1,  2,  3).  The  spaces  between  the  ribs  being  closed 
by  muscles,  called  intercostal  (between  ribs),  and  the  bottom 
of  the  chest  by  the  diaphragm  (Lith.  PL  1,  Fig.  4). 

409.  The  ribs  are  connected  to  the  back-bone  by  joints 
which  will  allow  them  to  move  up  and  down, 

Which  motions  increase  and  diminish  the  diameter  of  the  chest,  as 
may  be  perceived  by  placing  the  hands  upon  the  chest  and  raising  the 
ribs — as  when  the  breath  is  drawn  in. 

410.  The  ribs  are  raised  by  the  great  number  of  muscles 
which  connect  between  the  ribs  and  the  shoulders  and  back- 
bone  (Lith.  PL  2,  Fig.  1),  and  by  the  contraction  of  the 
muscles  between  the  ribs. 

Of  these  there  are  two  layers,  crossing  each  other  (Fig.  114).  The 
dotted  lines  represent  how  they  might  pass ;  but  as  a  muscle  can  only 
contract  for  about  one-third  its  length,  a  muscle  like  L  could  only  raise 
the  rib  through  one-third  the  intercostal  (between  rib)  space  ;  while  the 
contraction  of  the  muscles  m,  can  cause  the  ribs  to  almost  touch. 

Fig.  114. 


Fig.  114.— R,  R,  ribs.    M,  transverse  muscles.    L,  the  direction  they  might 
but  with  decided  loss  of  motion  to  the  ribs. 

411.  When  the  ribs  are  raised,  it  is  evident  that  the  muscles  passing 
from  the  ribs  to  the  pelvis  must  be  relaxed. 

412.  The  diaphragm  is  tendinous  in  its  central  part,  and 
at  the  portion  beneath  the  heart  is  capable  of  very  little 
motion.  Upon  either  side  of  this,  are  found  the  arches  of  the 
diaphragm.  The  sides  of  these  are  muscular.  When  they 
contract  the  arch  of  the  diaphragm  is  diminished  or  lowered, 
and  the  length  of  the  chest  is  increased. 


308  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

413.  It  is  evident,  as  before  shown,  that  the  parts  below  the  dia- 
phragm must  be  pressed  upon,  and  indeed  moved  down.     This  can  only 
take  place  if  the  sides  of  the  abdomen  yield,  to  wit,  if  the  muscles  relax. 
Hence  the  same  thing  is  necessary  that  the  ribs  may  be  raised,  as  is 
necessary  that  the  diaphragm  may  be  contracted. 

414.  Raising  the  ribs  and  contracting  the  sides  of  the 
diaphragm  by  enlarging  the  capacity  of  the  chest,  tends  to 
cause  a  cavity  in  it,  and  the  air  rushes  through  the  mouth  or 
nose  and  windpipe,  into  the  air-cells. 

The  more  extensive  the  motions  of  the  ribs  and  diaphragm,  the 
greater  the  quantity  of  air  entering  the  air-cells. 

415.  For  the  same  reason  that  the  air  tends  to  enter  the  air-cells,  the 
blood  will  flow  more  rapidly  into  the  network  about  the  cells,  when  the 
ribs  are  raised  and  diaphragm  lowered. 

416.  It  seems  then,  that  to  say  "drawing  in  the  breath" — as  is  the 
common  expression — is  not  quite  correct ;  a  person  merely  raises  the  ribs 
and  contracts  the  diaphragm,  and  the  air  is  instantly  pressed  or  pushed 
into  the  air-cells  by  its  own  weight. 

417.  There  are  two  causes  in  action,  to  throw  the  air  out 
of  the  air-cells. 

418.  In  the  first  place,  there  is  a  substance  filling  what 
would  otherwise  be  spaces,  between  the  divisions  of  the  wind- 
pipe and  between  the  air-cells.     It  is  called  the  parenchyma- 
tous  substance  of  the  lungs.     Its  great  peculiarity,  is  its 
elasticity. 

Some  suppose  its  apparent  elasticity  is  in  fact  owing  to  a  contractile 
power  of  some  part  of  the  sides  of  the  air-cells. 

419.  What  is  meant  by  its  elasticity  is  perceived,  if  a  person  attempt 
to  fill  the  air-cells  by  blowing  into  the  windpipe,  which  with  the  lungs 
has  been  removed  from  any  animal.     The  substance  of  the  lung,  on  ac- 
count of  its  elasticity,  presses  upon  the  sides  of  the  air-cells  to  such  a 
degree,  that  it  will  be  very  difficult  in  some  animals  to  fill  them  out ;  and 
the  instant  the  force  which  fills  them  ceases  to  act,  the  pressure  upon  the 
sides  of  the  air-cells  throws  the  air  out  of  them. 

420.  It  may  be  observed,  that  when  the  air  passes  into  the  lung,  it 
must  probably  overcome  the  elasticity  which  is  continually  acting,  though 
it  may  be,  that  the  elasticity  of  the  substance  of  the  lung  is  so  dependent 


SEC.  3.]  INHALATION  AND  EXHALATION  OF  AIR. 


369 


upon  the  nervous  system  that  it  can  be  increased  and  diminished,  if  not 
entirely  removed,  as  the  case  may  require. 

421.  In  the  second  place,  there  are  two  classes  of  mus- 
cles, which  co-operate  with  the  elasticity  of  the  lungs  in 
throwing  out  the  air  ;  one  class  acts  upon  the  ribs,  to  draw 
them  down  ;  the  other  class  presses  upon  the  organs  of  the 
abdomen,  causing  them  to  press  upon  the  diaphragm  and 
move  its  arches  upward. 

It  is  evident  that  the  muscles  which  raise  the  ribs,  as  also  the  sides 
of  the  diaphragm,  must  relax  when  the  air  is  thrown  out. 

422.  To  understand  perfectly  the  manner  in  which  the  air  is  caused 
to  pass  in  and  out  of  the  lungs,  it  must  be  noticed  that  the  air-passages 
and  cells,  and  air  in  them,  together  with  the  substance  of  the  lungs,  the 
bloodvessels,  and  the  blood  in  them,  fill  the  sides  of  the  chest  in  such  a 
manner  that  the  outside  of  the  lungs  is  constantly  in  contact  with  the 
inner  surface  of  the  chest  and  the  upper  surface  of  the  diaphragm. 

Fig.  115. 


423.  That  no  harm  may  be  produced  by  the  contact,  the  inside  of  the 
ribs  and  muscles  between,  is  lined  with  a  beautifully  delicate  membrane 

16* 


370  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

called  pleura  costalis  (rib).  It  is  reflected,  as  the  expression  is,  upon  the 
roots  of  the  lungs,  and  covers  them,  being  then  called  pleura  pulmonalis 
(lung).  The  surface  of  that  which  covers  the  lung  is  in  contact  with  the 
surface  of  that  lining  the  chest  and  the  diaphragm.  To  prevent  adhe- 
sion, and  allow  motion  upon  each  other  without  friction,  the  pleura  is 
constantly  moistened  with  a  glairy  fluid  called  serous,  formed  and  re- 
moved by  the  action  of  the  pleura. 

424.  It  will  now  be  understood,  that  as  the  lung  perfectly  fills  the 
chest,  the  instant  the  ribs  begin  to  rise  or  the  diaphragm  is  lowered, 
there  is  a  tendency  to  a  cavity  between  the  chest  and  lungs,  which  the 
air  prevents  from  existing,  by  pressing  into  the  lungs  and  filling  them  out 
as  rapidly  as  the  chest  enlarges.  As  soon,  on  the  other  hand,  as  the 
muscles  begin  to  contract,  which  draw  down  the  ribs  and  press  upon  the 
abdominal  organs,  it  would  seem  that  the  lungs  being  in  contact  with  the 
ribs  would  be  pressed  upon ;  but  upon  a  moment's  reflection  it  will  be  ob- 
served that  the  elasticity  of  the  lungs  will  not,  in  ordinary  cases,  allow  any 
pressure  to  take  place,  as  it  causes  the  lungs  to  contract  and  diminish  in 
size  as  rapidly  as  the  chest  follows.  The  lungs,  therefore,  are  so  nicely 
adjusted,  that  it  is  only  in  very  forcible  breathing  that  they  are  pressed 
upon  at  their  external  surface  ;  but  they  are  suspended,  as  it  were,  in  the 
chest,  in  most  delicate  contact  with  its  surface,  the  forces  which  are  act- 
ing upon  them  from  all  directions  being  so  justly  balanced,  that  the  lungs 
seem  sustained  in  the  midst  of  the  chest  without  support  from  any  parti- 
cular point.  The  roots,  as  they  are  called,  of  the  lungs,  are  loosely  con- 
nected with  the  back-bone  ;  but  they  do  not,  more  than  the  windpipe, 
Sustain  the  lungs  in  any  material  manner,  for  parts  of  the  lung  are  above 
them.  The  lungs  are  supported  by  the  resilience  of  their  substance,  the 
contraction  of  the  muscles,  and  the  pressure  of  the  air. 


SECTION  4. — Action  of  the  Blood  and  Air  upon  each  other. 

425.  Three  evident  effects  are  produced  upon  the  blood 
in  the  lungs.  Its  color  is  changed  from  a  purple  to  a  bright 
red,  its  temperature  is  raised,  and  it  is  diminished  in  quan- 
tity. 

Doubtless  other  effects  are  produced,  but  about  these  there  is  no  dis- 
pute. 


SEC.  4.]  ACTION  OF  THE  BLOOD  AND  AIR.  371 

426.  The  degree  of  effect  depends  upon  the  quantity  and 
quality  of  the  blood,  upon  the  constitution  and  condition  of 
the  lungs,  upon  the  health  of  the  body  generally,  and  upon 
the  quantity  and  quality  of  air  to  the  action  of  which  the 
blood  has  been  subjected  in  the  lungs. 

427.  The  quantity  and  quality  of  the  "blood.      Both  these 
things  depend  upon  the  quantity  and  quality  of  the  food  and 
drink,  upon  the  exercise  a  person  has  taken,  and  the  fulfil- 
ment of  the  duties  of  the  other  organs. 

a.  It  has  heretofore  been  shown,  that  certain  articles  of  food  were 
used  to  warm  the  body.     If  these  are  scarce  in  the  bloodvessels,  it  could 
not  be  expected  that  an  abundance  of  heat  would  be  produced  in  the 
lungs.     Hence  why  a  person  feels  warmer  for  eating  heartily  in  cold 
weather. 

b.  The  quantity  of  drink  affects  the  quantity  of  blood  in  the  vessels, 
and  of  course,  other  things  being  similar,  will  affect  the  amount  of  sub- 
stance adapted  to  produce  heat  passing  through  the  lungs  in  a  given  time. 
Hence  in  cold  weather  there  should  be  less  water  in  the  blood  than  in 
warm  ;  consequently  there  is  little  thirst  in  winter,  and  those  who  without 
thirst  drink  largely  of  tea,  coffee,  &c.,  suffer  more  from  the  cold.     Nature 
also  calls  on  the  kidneys  to  relieve  the  bloodvessels  of  a  part  of  their  fluid, 
when  the  system  is  exposed  to  the  cold. 

c.  The  exercise  a  person  takes  does,  of  course,  by  wearing  out  the 
system,  affect  the  quality  and  quantity  of  the  blood  ;  but  whether  in  such 
a  manner,  other  than  by  increasing  the  rapidity  of  the  circulation,  as  to 
increase  the  amount  of  substance  concerned  in  producing  heat  in  the 
lungs,  is  not  known.     The  more  actively  a  person  exercises,  the  warmer 
does  he  become  ;    but  there  are  three  ways  of  accounting  for  it — either 
because  the  circulation  is  caused  to  be  more  rapid,  because  as  the  parts 
are  decomposing,  heat  is  produced,  or  because  the  wearing  or  exercised 
parts  supply  to  the  blood  an  increased  quantity  of  material,  by  which,  in 
the  lungs  heat  is  produced. 

d.  The  fulfilment  of  the  duties  of  the  organs  will  have  a  striking  ef- 
fect upon  the  quantity  and  quality  of  the  blood.     As  just  illustrated,  the 
kidneys  sometimes  diminish  the  quantity  of  the  blood  surprisingly,  with- 
out in  the  least  affecting  those  parts  of  its  ingredients  concerned  in  pro- 
ducing heat ;  while  on  the  other  hand,  by  not  performing  their  duty,  they 
may  allow  the  fluid  of  the  blood  to  increase  till  there  is  nothing  like 


372  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

the  proper  quantity  of  heat-producing  material  passing  through  the  Iung8 
in  a  given  time.  The  heat-producing  material,  or  the  fuel,  as  it  may  be 
called,  of  the  blood,  may  be  removed  by  some  organ,  for  instance  the 
carbon  by  the  liver,  and  the  lungs  thus  receive  a  less  quantity  than  they 
ought,  &c. 

428.  The  activity  of  the  heart  greatly  influences  the 
quantity  of  blood  which  in  a  given  time  passes  through  any 
organ. 

429.  The  lungs  of  different  persons  constitutionally  vary 
in  respect  to  size,  the  capacity  of  the  bloodvessels,  the  ease 
with  which  blood  circulates  through  them,  the  degree  of  ner- 
vous energy  exerted  upon  them,  &c.,  while  the  condition  of 
the  lungs  varies  under  the  action  of  all  the  causes  of  health 
and  disease. 

430.  The  health  of  the  body  generally  will,  by  the  influ- 
ence of  the  nervous  system,  produce  a  most  important  effect 
upon  the  changes  taking  place  in  the  lungs. 

A  person  who  is  exhausted,  therefore,  will  not  be  able  to  warm  him- 
self in  a  perfect  manner,  and  must  therefore  be  careful  of  exposure  and 
protect  himself  by  an  abundance  of  clothing.  People  soon  feel  chilly 
if  they  are  exposed  when  exhausted,  and  readily  "  take  cold." 

431.  That  the  quantity  and  quality  of  the  air  have  a  great  influence 
upon  the  changes  the  blood  undergoes  in  the  lungs,  is  evident  from  the 
changes  taking  place  in  the  air  while  in  the  lungs.  To  understand  these, 
it  is  necessary  first,  to  consider  the  constitution  of  the  air  ;  second,  the 
manner  in  which  heat  is  usually  produced. 

432.  Air  is  composed  of  two  simple  elements,  and  one 
compound  element  in  very  small  proportion.  About  eighty 
parts  in  a  hundred  of  the  air  is  composed  of  a  kind  of  air  or 
gas  called  nitrogen,  a  simple  element,  and  apparently  of  no 
use  except  to  dilute  the  oxygen,  the  name  of  the  other  simple 
element,  a  gas  or  air  composing  about  twenty  parts  in  a  hun- 
dred of  the  atmosphere.  The  compound  element  is  also  a 
gas,  called  carbonic  acid,  and  forms  about  one  part  in  two 
thousand  of  pure  air. 

It  is  compounded  of  oxygen  and  carbon,  a  simple  element  or  sub- 


SEC.  4.]  ACTION  OF  THE  BLOOD  AND  AIR.  373 

stance  which  composes  the  greater  part  of  coal,  and  gives  to  it  its  chief 
characteristics. 

433.  When  the  air  leaves  the  lungs,  it  is  very  different ; 
instead  of  twenty  parts  in  a  hundred,  it  contains  but  sixteen 
of  oxygen,  and  contains  nearly  four  parts  of  carbonic  acid. 
It  is  very  full  of  moisture,  as  may  be  seen  by  breathing  upon 
glass,  &c.     Its  proportion  of  nitrogen  has  not  changed  in  an 
appreciable  degree. 

If  a  person  blow  the  air  from  the  lungs  through  lime-water,  it  turns 
to  a  milky  color,  and  if  it  be  allowed  "  to  stand,"  a  chalky  substance 
will  be  seen  at  the  bottom.  This  is  found  upon  examination  to  be 
formed  of  carbonic  acid  and  lime,  the  same  as  limestone,  marble,  &c. 
The  lime  was  in  the  lime-water,  and  the  carbonic  acid  must  have  been 
in  the  air  breathed  from  the  lungs. 

If  a  person  apply  his  mouth  to  the  mouth  of  a  bell-glass,  bottle,  or 
decanter,  the  bottom  of  which  is  wanting  or  has  a  hole  broken  in  it,  and 
then  push  the  bottom  a  short  distance  into  a  pail  of  water,  he  can  draw 
all  the  air  in  the  bottle  into  his  lungs,  from  which  he  can  breathe  the  air 
back  into  the  bottle.  This  must  be  so  held  in  the  water  that  it  shall 
follow  up  into  the  bottle  as  the  air  is  drawn  out,  and  when  the  bottle  is 
again  filled  with  air,  it  must  be  held  quite  steady,  with  the  mouth  yet 
applied  to  it  and  the  bottom  yet  in  the  water.  In  the  meantime,  let  a 
match  be  lighted,  and  when  it  is  burning  well,  remove  the  mouth  and 
drop  the  bottle  a  little,  for  instance,  an  inch  into  the  water,  and  thrust 
the  match  into  the  mouth  of  the  bottle,  when,  if  the  experiment  have 
been  well  managed,  the  match  will  instantly  go  out,  showing  that  the 
air  is  so  changed  in  the  lungs  that  a  match  will  not  burn  in  it ;  and  what 
is  exceedingly  surprising,  a  person  cannot  draw  the  air  into  the  lungs 
and  throw  it  out  so  quickly  that  the  match  will  burn  in  it.  To  know 
why  this  is,  we  must,  in  the  second  place,  consider  how  heat  is  produced. 

434.  It  is  found  by  experiment,  that  when  certain  sub- 
stances unite  together  they  always  produce  heat. 

This  is  explained  by  supposing  that  the  substances,  when  separate, 
contain  more  heat  than  when,  united,  they  are  able  to  retain.  For  in- 
stance, when  hydrogen  and  oxygen  unite  to  form  water,  they  produce 
heat,  each  having  a  certain  amount  of  heat  which  it  retains  while  it  is 
in  a  separate  state ;  but  when  they  unite,  they  lose  their  power  of  retaining 
as  much  as  they  could  when  separate.  On  the  other  hand,  if  water  be 


374  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

separated  into  oxygen  and  hydrogen,  they  will  require  a  certain  amount 
of  heat  more  than  they  had  when  forming  water ;  and  the  required 
amount  they  will  take  or  draw  from  any  thing  around  them  which  is  not 
stronger  to  retain  than  they  are  to  obtain. 

435.  When  carbon  and  oxygen  unite  to  form  carbonic  acid,  heat  is 
produced  upon  the  same  principle ;  and  on  the  other  hand,  coldness  is 
caused  when  carbonic  acid  is  changed  into  carbon  and  oxygen ;  and 
though  there  is  scarcely  a  change  taking  place  in  nature,  that  is  not 
attended  with  a  change  of  temperature,  yet  heat  is  usually  and  chiefly 
produced  by  the  formation  of  water  and  carbonic  acid. 

436.  This  will  be  illustrated  by  observing  how  a  candle  is  burned, 
and  for  simplicity,  one  particle  of  fat  may  first  be  taken.     It  is  composed 
of  oxygen,  carbon,  and  hydrogen,  closely  united.     In   order  to  separate 
them  from  each  other,  a  lighted  match  is  held  near  to  the  particle  of  fat, 
as  the  heat  of  the  match  has  a  tendency  to  separate  the  particles  of  any 
substance.     When  the  components  of  the  fat  are  separated  to  a  given 
distance,  they  will  not  return  to  their  former  condition  ;   but  the  oxygen 
arid  hydrogen  have,  by  nature,  so  strong  a  tendency  to  unite,  that  they 
will  do  so,  and  thus  form  water,  while  the  carbon  will  be  left  by  itself,  in 
the  form  of  soot,  lampblack,  or  coal,  if  there  be  no  air  about  it ;  but  if 
there  be,  the  oxygen  of  the  air  will  unite  with  the  carbon,  producing 
carbonic  acid,  and  thus  the  fat  will  be  burned  up.     The  heat  which  is 
produced  by  the  burning  of  the  first  particle  will  act  upon  the  second 
particle,  and  separate  its  oxygen,  hydrogen,  and  carbon,  which  will  unite 
with  each  other  and  the  oxygen  of  the  air,  form  water  and  carbonic 
acid,  thus  producing  heat,  which  acts  on  the  surrounding  particles,  which 
pass  through  the  process,  until,  at  last,  particle  after  particle,  the  whole 
candle  is  burned. 

437.  A  similar  process  takes  place  when  wood  is  burned,  for  wood 
is  composed  of  carbon,  hydrogen,  and  oxygen,  with  some  other  articles, 
which  form  the  ashes.     This  is  proved,  by  noticing  what  a  quantity  of 
vapor  rises  from  a  chimney  of  a  cold  morning  when  the  water  from  the 
wood  is  condensed  ;  also,  how  much  water  will  trickle  from  a  stove-pipe, 
when  so  long  as  to  condense  the  vapor  produced  by  the  burning  wood. 
If  the  contents  of  the  stove-pipe  be  caused  to  pass  through  lime-water, 
the  same  appearance  is  exhibited  as  when  a  person  breathes  through  it, 
showing  that  carbonic  acid  exists  in  the  pipe,  and  is  formed  by  burning 
the  wood. 

438.  If,  however,  the  air  be  not  admitted  to  the  burning  wood,  as  in 
an  air-tight  stove  or  in  a  coal-pit  may  be  the  case,  water  only  will  be 


SEC.  4.]  ACTION  OF  THE  BLOOD  AND  AIR.  375 

formed,  and  the  carbon  will  remain  behind  in  the  form  of  coal.  If  a 
coal-pit  be  noticed  of  a  cold  day,  a  large  amount  of  vapor  will  be  seen 
rising  from  it,  owing  to  the  water  formed  from  the  wood  finding  its  way 
out.  It  is  not  certain,  however,  but  a  small  portion  of  the  oxygen  of  the 
wood  may  unite  with  its  carbon,  and  it  may  be  that  a  small  quantity  of 
the  oxygen  of  the  air  unites  with  the  hydrogen  of  the  wood. 

439.  It  is  certain  that  the  larger  the  quantity  of  air  present,  the  more 
rapidly  will  any  thing  burn ;  for  a  strong  draught  causes  wood,  coal,  and 
the  contents  of  a  lamp  to  burn  with  greater  energy  and  corresponding 
heat ;  and  that  this  depends  upon  the  oxygen  of  the  air,  is  proved  by  the 
experiment  already  mentioned  with  the  match,  bottle,  &c.  It  follows, 
therefore,  that  the  greater  the  quantity  of  oxygen  acting  on  any  article 
used  as  fuel,  the  greater  is  the  effect. 

440.  Every  argument  proves  that  the  greater  the  quantity 
of  oxygen  acting  in  the  lungs,  in  a  given  length  of  time,  the 
greater  the  amount  of  heat  produced,  other  things  being  equal. 

a.  The  food  eaten  with  the  evident  intent  that  it  shall  warm  the 
system,  is  such  as  contains  oxygen,  hydrogen,  and  carbon. 

6.  The  various  parts  of  the  body  which  are  worn  out  or  decomposed 
by  exercise,  which  is  productive  of  heat,  contain  carbon,  oxygen,  and 
hydrogen,  and  at  such  times  there  is  a  more  active  circulation  of  blood 
through  the  lungs,  and  breathing  is  more  rapid. 

c.  In  summer  the  liver  is  more  active,  in  proportion,  than  in  winter, 
and  removes  more  carbon ;  evidently  because,  if  the  carbon  should  be 
removed  by  the  lungs,  heat  would  be  produced  when  it  is  not  needed. 

d.  The  substances  which  pass  from  the  lungs,  are  such  as  would 
result  from  a  combination  of  the  oxygen  of  the  air  with  the  constituents 
of  the  blood  ;  and  there  is  a  corresponding  disappearance  of  the  oxygen 
which  entered  the  lungs. 

e.  Whatever  facilitates  the  entrance  of  blood  into  the  lungs,  has  an 
equally  good  effect  upon  the  admission  of  the  air. 

/.  In  warm  weather,  the  air  is  correspondingly  rarefied,  and  only  a 
small  quantity  of  air  enters  the  lungs  at  one  inhalation  of  the  breath ; 
while  in  cold  weather,  a  large  quantity  of  air  enters  the  lungs.  In  cold 
weather,  the  air  is  expanded  after  it  is  received  into  the  lungs,  as  any 
one  can  test,  by  placing  the  hands  upon  the  sides,  and  inhaling  the  cold 
air  suddenly ;  the  chest  will  be  felt  to  enlarge  afterward.  By  this  means, 
the  air  is  brought  more  forcibly  in  contact  with  the  inner  surface  of  the 
cells,  and  produces  a  more  powerful  effect  upon  the  blood  circulating 


376  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

around  them.  In  summer,  the  air  being  warm  expands  but  little,  and  but 
little  effect  is  produced  ;  a  most  admirable  adaptation  of  things  to  the  ne- 
cessities of  man. 

441.  The  next  question  would  be,  What  causes  the  changes  to  take 
place   between    the    blood  and  air  ?     The  answer  would  be,  that   the 
changes  are  either  necessary,  from  the  constitution  of  the  blood  and  air, 
or  they  ure  under  the  control  of  the  nervous  system  of  organic  life. 

442.  Again,  it  may  be  asked,  Why  does  not  tho  heat  in  the  lungs, 
if  produced  by  the  action  of  the  blood  upon  air,  exhibit  itself  more  dis- 
tinctly 1     The  answer  is,  that  the  blood  moves  through  the  lungs  so 
rapidly,  that  the  heat  is  removed  from  them  almost  as  fast  as  produced. 

,  443.  Some  think  that  very  little  if  any  heat  is  produced  in  the  lungs 
directly  ;  but  that  the  constituents  of  the  air,  unite  with  the  blood  in  the 
lungs,  and  with  it  are  carried  into  various  parts  of  the  body,  where  they 
serve  the  important  purpose  of  producing  heat,  while  the  substances  pro- 
duced are  brought  by  the  blood  to  the  lungs,  from  which  they  are  re- 
moved when  the  air  is  expired  ;  but  all  parties  allow  the  lungs  to  be 
equally  important.  And  when  it  is  remembered  how  rapidly  the  blood 
moves  through  the  lungs,  the  exceedingly  great  quantity  of  it  passing 
through  the  lungs  in  the  course  of  twenty-four  hours,  and  that  the  blood 
of  the  entire  body  circulates  through  the  lungs  each  time  it  visits  the 
heart,  the  importance  of  these  organs  must  be  in  a  measure  appreciated, 
as  well  as  the  consequence,  in  particular,  of  having  them  supplied  with 
a  large  quantity  of  pure  air.  We  may,  therefore,  now  consider  what  will 
facilitate,  and  what  will  prevent  the  action  of  pure  air  in  large  quanti- 
ties. 

444.  It  is  evident  there  must  be  some  cause  acting  in  the  lungs,  to 
cause  the  air  to  unite  with  the  components  of  the  blood.  The  nervous 
systom  of  organic  life  is  supposed  to  be  the  direct  agent  in  this  case  ;  it 
therefore  follows  that, 

445.  The  more  healthy  and  vigorous  the  general  health, 
the  more  active  will  be  the  changes  taking  place,  between 
the  air  and  blood. 

If  any  portion  of  the  lungs  be  diseased,  there  cannot  be  a  free  circula- 
tion of  blood  or  air  through  the  diseased  part ;  from  which  it  follows, 

446.  The  more  healthy  the  lungs,  the  greater  the  effect 
produced  in  them. 

It  sometimes,  indeed  frequently  happens,  that  if  some  part  of  the  lung 


SEC.  4.]        ACTION  OF  THE  BLOOD  AND  AIR.  o77 

be  diseased,  the  other  parts  perform  their  duties  more  actively,  or  the 
motion  of  the  chest  is  increased,  that  the  want  of  action  in  the  diseased 
part  may  be  compensated.  For  instance,  in  case  of  asthma,  the  shoul- 
ders frequently  grow  out.  When  a  person  is  affected  by  consumption,  a 
peculiar  stoop  is  observed,  not  like  that  of  negligence,  but  the  "  consump- 
tive round  shoulders."* 

In  the  next  place,  it  must  be  evident  that  if  the  bloodvessels  of  the 
lungs  are  too  much  filled  with  blood,  the  air-cells  will  not  be  allowed  to 
distend  with  air ;  it  therefore  follows  that, 

447.  A  proper  circulation  of  blood  through  the  lungs  is 
important,  and  all  causes  which  tend  to  derange  it,  must  be 
injurious. 

e.  g.  When  a  person  has  taken  cold  by  exposure  of  the  skin,  and 
the  blood  has  been  driven  inward,  there  seems  to  be  a  fulness  of  the 
chest,  and  the  breath  is  inhaled  with  difficulty,  and  any  thing  which  re- 
stores the  circulation,  gives  immediate  relief. 

But  as  the  inhalation  of  the  air  depends  upon  the  movement  of  the 
chest  and  depression  of  the  diaphragm, 

448.  Whatever  checks  the  elevation  of  the  chest,  or  de- 
pression of  the  diaphragm,  prevents  a  perfect  action  of  the 
air  upon  the  blood ;  and  whatever  assists  the  elevation  of  the 
chest,  and  depression  of  the  diaphragm,  increases  the  action 
of  the  air  and  blood  upon  each  other. 

Every  bandage  or  snugly  fitting  article  of  dress  must  be  injurious,  for 
if  upon  the  chest  they  prevent  its  movements,  if  upon  the  abdomen  they 
prevent  the  distension  of  its  sides,  without  which  the  diaphragm  cannot 
contract,  as  has  been  shown.t  Much  worse  must  any  thing  be  which 
lessens  the  size  of  the  chest,  which  can  readily  be  done,  especially  in 
early  life,  for  the  ribs  yield  at  their  joints  with  the  back-bone,  and  though 

*  Such  being  the  cause  of  the  round  shoulders  of  consumption,  how 
erroneous  to  attribute  the  disease  to  the  deformity,  and  how  foolish  to 
attempt  to  cure  a  person,  or  benefit  him,  if  consumptive,  by  making  him 
straight,  when  nature  has  made  him  become  crooked  to  lengthen  his  life. 
While  the  disease  remains,  it  would  be  a  misfortune  to  change  his  form. 

t  How  absurd  the  pretensions  of  some,  to  improve  the  lungs  by  any 
articles  producing  pressure  on  the  abdomen,  fictitiously  called  supporters, 
or  by  the  use  of  any  shoulder-braces,  with  bandages  girding  the  abdo- 
men, or  indeed  applied  in  any  way. 


378 


THE  RESPIRATORY  ORGANS. 


[CHAP.  in. 


bony,  they  are  themselves  pliable,  while  the  cartilages  which  connect 
them  with  the  breast-bone  are  very  easily  bent :  thus  are  produced  the 
most  pity-causing  deformities  (Fig.  116  and  Fig.  117).  The  movements 
of  the  diaphragm  are  especially  prevented  by  any  fulness  of  the  abdom- 
inal organs,  as  it  distends  the  sides  of  the  abdomen,  and  it  is  difficult  for 
the  diaphragm  to  distend  them  still  more,  as  it  must  if  it  contract.  Hence 
a  person  is  troubled  for  breath  after  eating  very  heartily.  The  elasticity 
of  i he  lungs  is  also  such,  at  times,  as  to  be  very  difficult  to  overcome  ; 
and  whoever  will  endeavor  to  fill  out  the  lungs  of  an  ox,  or  even  a  calf, 
will  appreciate  better  than  in  any  other  way  the  power  required  in  some 
cases.  On  the  other  hand,  a  perfect  freedom  from  the  stricture  or  weight 
of  clothing,  and  much  exercise  of  the  respiratory  muscles,  must  supply  the 
lungs  with  a  sufficient  quantity  of  air.  Hence  the  importance  of  singing, 
reading  aloud,  going  up  and  down  hill,  indeed,  doing  any  thing  which 
shall  exercise  the  muscles  of  the  chest  and  diaphragm.  It  must  be  evi- 
dent the  chest  cannot  be  easily  or  greatly  elevated,  nor  the  diaphragm 
contracted,  when  a  person  stands  perfectly  straight,  for  then  the  muscles 
of  the  abdomen  are  made  comparatively  tense,  and  it  will  be  difficult 
to  distend  the  sides  of  the  abdomen.*  A  singer  is  observed  to  bend  for- 
ward a  little  when  the  breath  is  taken  in. 


Fig.  116. 


Fig.  117. 


*  Again,  is  seen  the  folly  of  wearing  supporters,  shoulder-braces,  or 
any  thing  which  shall  keep  a  person  perfectly  straight. 


SEC.  4.]        ACTION  OF  THE  BLOOD  AND  AIR.  .        379 

But  the  question  is  not  merely,  how  may  the  capacity  of  the  lungs  be 
increased,  but  rather  how  may  a  large  quantity  of  air  be  frequently 
changed  in  the  lungs  ;  from  which  it  follows  that, 

449.  Whatever  facilitates  the  expulsion  of  the  air  from 
the  lungs  is  advantageous,  while  any  thing  that  prevents  this 
is  injurious. 

The  contraction  of  the  abdominal  muscles,  assisted  by  that  of  some 
o  the  muscles  upon  the  back,  draw  down  the  elevated  chest,  provided 
the  back  be  not  too  much  curved  ;  and  the.straighter  it  is,  the  more  pow- 
erfully will  the  muscles  act ;  for  a  muscle  is  always  more  efficient  when  it 
first  begins  to  contract,  than  when  contracted  to  almost  its  entire  degree. 
Hence  a  singer  will  straighten  himself,  that  the  breath  may  be  thrown 
out  with  greater  force.  In  order,  however,  that  the  muscles  of  the 
abdomen  may  have  their  greatest  force  on  the  diaphragm,  the  abdominal 
organs  must  be  more  or  less  full ;  as,  if  they  are  nearly  empty,  the 
muscles  will  contract  in  a  straight  line,  from  the  edge  of  the  ribs  to  the 
hips,  without  pressing  with  force  upon  the  abdominal  organs  ;  but  when 
they  are  full,  the  muscles  are  distended  outward,  and  when  contracting, 
necessarily  press  the  organs  inward,  and  exert  a  force  upward  against 
the  diaphragm.  A  reasonable  fulness  of  the  abdominal  organs,  and  a 
reasonable  erectness  of  form,  is  to  be  recommended ;  but  a.  frequent  change 
of  position  is  the  best  rule  of  life.  When  the  abdominal  organs  are  full, 
a  person  need  not  be  as  erect  as  when  they  are  empty.  Exercise  of  the 
muscles  of  expiration  will,  of  course,  render  them  more  effective. 

When  air  is  taken  into  the  lungs,  it  expands  if  it  be  cooler  than  they 
are  ;  and  the  greater  the  difference  of  temperature,  the  greater  the  ex- 
pansion, and  the  greater  the  expansion,  the  more  forcibly  is  the  air 
brought  in  contact  with  the  sides  of  the  air-cells,  and  the  greater  the 
effect  produced  upon  the  blood  which  circulates  about  them.  Whence  it 
follows  that, 

450.  The  colder  the  weather,  the  greater  the  changes  of 
the  blood  and  air  in  the  lungs. 

Hence  cold  air  is  found  to  be  most  bracing  ;  hence  one  reason  why 
morning  air  is  more  effective  than  that  of  any  other  part  of  the  day. 
These  things  show  the  wise  adaptation  of  all  things  to  each  other,  and 
inspire  a  confidence  in  the  laws  of  the  Creator  that  is  very  gratifying. 

But  the  utility  of  the  air  in  the  lungs  depends  upon  certain  of  its 
parts  uniting  with  the  components  of  the  blood  ;  it  is  not,  therefore,  the 


380  THE  RESPIRATORY  ORGANS.  [CHAP.  III. 

quantity  of  the  air  merely,  but  also  the  quality  which  must  be  con- 
sidered ;  and  it  has  been  proved,  that  the  air  coming  from  the  lungs  is 
not  suitable  to  be  received  again ;  and  as  a  large  quantity  is  used  in  the 
lungs  in  a  very  little  time,  it  follows  that, 

451.  All  rooms  should  be  perfectly  ventilated,  by  having 
communication  with  the  grand  reservoir — the  atmosphere 
surrounding  the  earth. 

This  should  evidently  be  more  carefully  attended  to  during  the  night 
than  during  the  day,  as  then  the  opening  and  shutting  of  doors,  and  the 
fires  of  cold  weather,  will  tend  to  purify  or  change  the  air  in  a  room. 
During  the  night,  also,  the  state  of  repose  prevents  the  lungs  frojh  re- 
ceiving as  much  air  as  while  a  person  is  stirring  during  the  day  ;  and 
the  comparatively  inactive  state  of  the  nervous  system  prevents,  to  a 
degree,  those  changes  which  take  place  during  the  day.  These  prin- 
ciples are  most  inexcusably  neglected  by  many  of  those  who  have  the 
charge  of  constructing  public  buildings,  and  by  nearly  all,  in  the  arrange- 
ment of  their  sleeping  apartments,  which  by  some  persons  are  supplied 
with  double  windows,  and  every  chink  or  cranny  closed  as  securely  as  if 
the  air,  our  greatest  blessing,  were  our  greatest  enemy.*  But  experiment 
and  accident  have  proved  that  the  carbonic  acid  breathed  out  from  the 
lungs  is  very  poisonous  when  used  in  very  small  quantities.  So  small  a 
proportion  as  10  per  cent,  will  destroy  the  life  of  animals,  and  many 
human  beings  have  lost  their  lives  by  going  into  wells,  tombs,  and  other 
places  where  it  existed.  The  burning  of  most  articles  produces  more  or 
less  of  it ;  coal  being  carbon,  produces  a  great  deal  when  burning,  and  a 
pan  of  coals  placed  in  a  chamber  has  produced  so  much  as  to  destroy 
life.t  If  a  grate  do  not  draw,  the  gas  is  likely  to  pass  into  the  room 
without  causing  any  smoke — a  great  cause  of  headaches,  &c. 


*  In  regard  to  pure  air  and  water,  unadulterated  by  tea,  coffee,  &c., 
the  old  adage  seems  true,  "  Nothing  cost,  nothing  worth."  If  air  could 
be  monopolized  and  sold  by  the  gallon,  its  value  would  soon  be  appre- 
ciated. 

t  When  a  person  is  injured  by  such  a  cause,  place  his  feet  and  hands 
in  warm  water,  rub  him  briskly,  and  apply  cold  cloths  to  his  head,  and 
produce  artificial  breathing.  This  is  done  by  pressing  upon  the  chest  and 
abdomen,  and  then  removing  the  pressure  suddenly,  when  the  elasticity 
of  the  chest  and  the  lungs  will  inhale  a  portion  of  air.  The  pressure 
and  removal  of  it  must  be  made  at  such  intervals  as  to  imitate,  as  near 
as  possible,  common  breathing. 


SEC.  4.]       ACTION  OF  THE  BLOOD  AND  AIR.  381 

It  seems,  therefore;  that  there  is  not  any  particular  size  of  chest  that 
is  desirable,  but  that 

452.  A  healthy  state  of  the  body  generally,  with  active 
exercise  of  all  parts  of  the  body,  but  particularly  the  mus- 
cles of  inspiration  and  expiration,  and  ventilated  apartments, 
are  the  chief  things  which  conduce  to  the  perfect  action  of 
the  air  and  blood  upon  each  other  in  the  lungs. 

And  as  it  has  been  seen,  that  one  of  the  chief,  if  not  the  chief  duty 
of  the  lungs  is  to  produce  heat,  it  follows, 

453.  If  a  person  would  be  warm,  he  must  preserve  his 
general  health,  take  exercise,  and  breathe  pure  air. 

It  is  to  be  inferred  that  a  person  will  sleep  warmer,  the  coldest  night 
in  winter,  with  his  apartment  ventilated,  which  cannot  be  done  perfectly 
except  there  be  communication  with  out-doors.  Especially  during  the 
night  will  a  person  be  kept  warmer  and  be  in  less  danger  of  taking  cold, 
if  a  sleeping  apartment  be  ventilated,  not  in  such  a  manner  that  a  draught 
of  air  shall  come  upon  a  person,  but  at  the  same  time  perfectly.* 

*  A  window  may  be  raised  with  safety,  if  an  outside  or  inside  shutter 
be  closed,  or  a  wide  board  placed  against  the  casing  a  little  distance 
from  the  sash.  If  the  upper  sash  be  lowered  and  the  lower  sash  raised, 
the  change  of  air  is  more  perfect ;  but  a  board  or  shutter  must  be  so 
placed  in  respect  to  the  upper  sash,  that  the  air  cannot  sweep  across  the 
room,  as  it  will  be  inclined  to  do,  and  striking  against  the  opposite  wall, 
fall  downward,  producing  a  current.  The  position  of  the  bed  should  be 
such  that  a  person  cannot  be  affected  by  such  currents  ;  they  will  be 
produced  across  a  large  room  in  many  cases,  and  if  the  bed  be  against  or 
very  near  the  wall,  a  person  in  it  will  feel  the»  current  almost,  if  not  quite 
as  sensibly,  as  if  near  the  window. 


CHAPTER  IV. 

THE  VOICE. 

454.  Speech  is  produced  by  the  combined  action  of  some  of  the  first 
and  some  of  the  second  class  of  organs.     The  principle  upon  whicu  they 
act  is  very  simple — merely  this  : 

455.  Air,  when  forced  through  an  opening  or  passage,  will  produce 
sound,  viz.,  will  be  thrown  into  such  waves  or  vibrations  that  the  nerve 
of  the  ear  will  be  acted  upon. 

456.  The  character  of  the  sound  will  depend  on  the  dimensions  and 
form  of  the  opening  or  passage,  the  nature  of  the  substance  in  which  the 
opening  exists,  the  degree  of  force  with  which  the  air  passes  through,  and 
the  kind  of  air. 


SECTION  1. — Expulsion  of  Vocal  Air. 

457.  The  breathing   apparatus   is  perfectly   adapted  to 
perform  a  part  in  the* production  of  speech.     The  lungs  are 
admirable  reservoirs  for  containing  air,  which  can  be  forced 
out  by  the  expiratory  muscles  with  any  degree  of  sudden- 
ness. 

For,  by  closing  the  open  part  of  the  windpipe,  the  air  can  be  forced 
against  the  valve,  when  by  quickly  dropping  the  windpipe,  a  larger  or 
smaller  portion  of  air  will  gush  out. 

458.  Whatever,  therefore,  is  for  the  good  of  the  respira- 
tory apparatus,  benefits  a  person  in  respect  to  the  voice,  so 
far  as  throwing  out  the  air  with  force  is  concerned. 

459.  That  the  respiratory  muscles  may  be  effective  in 


SEC.  2.]  MODIFIERS  OF  SOUND.  383 

producing  speech,  they  must  be  under  the  direct  control  of 
the  mind. 

They  therefore  belong  to  the  class  of  mixed  muscles,  viz.,  those  which 
in  health  and  ordinarily,  contract  either  voluntarily  or  involuntarily. 


SECTION  2. — Modifiers  of  Sound. 

460.  The  passage  through  which  the  air  passes,  in  its 
emission  from   the  lungs,  producing  sound  when   forcibly 
emitted,  may  be  considered  in  four  respects. 

461.  1st.  There  is  an  arrangement  near  the  top  of  the 
windpipe,  below  the  valve    against  which   the  windpipe  is 
drawn  to  close  itself,  within  the  larynx,  by  which  the  air  is 
acted  upon  when  any  tones  are  produced. 

When  a  person  makes  the  sound  of  A,  the  windpipe  is  first  raised 
and  closed,  the  expiratory  muscles  contract  and  force  the  air  upward ; 
the  windpipe  is  dropped  more  or  less,  and  the  air  gushes  out,  producing 
such  a  sound  as  desired,  because  the  apparatus  within  the  larynx  has 
been  by  the  action  of  proper  muscles,  placed  in  that  state  which  expe- 
rience teaches  to  be  necessary. 

462.  2d.  After  the  air  has  passed   the   outlets   of  the 
windpipe,  it  may  be  acted  upon  in  the  back  part  of  the 
throat  and  its  sound  modified, 

As  will  be  appreciated  by  making  the  sound  of  the  letter  B.  It  is 
not  full  and  prompt,  but  subdued,  and  with  others  of  its  class,  called 
sub-tone. 

463.  3d.  The  air  may  be  obstructed,  not  at  the  wind- 
pipe, but  in  the  front  part  of  the  mouth,  and  again  allowed 
to  pass  on  suddenly,  producing  a  class  of  "  whisper  sounds/' 

As  vwien  the  letter  F  is  spoken.  All  this  class  of  sounds  are  called 
aspirates. 

464.  4th.  The  character  of  each  sound  of  each  class  is 
more  or  less  affected  by  the  structure,  shape,  and  size  of  the 


884  THE  VOICE.  [CHAP.  iv. 

windpipe,   the  opening   from   it,  the  throat,  the   nose,  the 
mouth,  and  as  some  think,  the  whole  head. 

The  character  of  the  voice  is  also  affected  by  the  capacity  of  the 
lungs  and  the  structure  of  the  chest ;  for  if  the  volume  of  air  in  the  lungs 
be  large,  and  the  chest  firm  and  sonorous  when  struck,  the  voice  has 
more  rulness  and  resonance. 

465.  These  things  affect  merely  the  richness,  the  fulness,  and  peculiar 
character  of  the  tones  of  the  voice,  enabling  us  to  readily  distinguish 
one  person  from  another  by  his  voice,  but  not  such  as  to  ever  affect  in  the 
least  the  understanding  of  the  ideas  expressed  by  a  person.     Nor  can 
the  form,  shape,  or  size  of  any  of  these  parts,  except  probably  the  upper 
part  of  the  windpipe,  be  affected  by  a  person's  efforts. 

466.  As  the  arrangement  of  the  larynx  which  affects  the  production 
of  desirable  sounds,  is  made  by  the  action  of  muscles,  so  also  is  that  of 
the  throat  and  front  part  of  the  mouth.     It  would  seem,  therefore,  that 

467.  The  production  of  voice,  to  wit,  the  inhalation  and 
exhalation  of  air,  the  closing  and  opening  the  windpipe,  the 
modification  of  the  larynx,  throat,  and  mouth,  is  wholly  de- 
pendent on  the  action  of  muscles  which  are  dependent  on 
nervous  influence  caused  to  act  by  the  mind,  on  the  recep- 
tion of  blood,  and  on  the  nervous  influence  of  organic  life. 

All  the  rules,  therefore,  which  apply  to  muscles  heretofore  considered, 
must  apply  to  these,  viz.,  they  must  be  exercised — lightly  at  first; — gra- 
dually increased,  and  never  beyond  the  point  of  fatigue. 

468.  These  muscles  are  made  impulsive  by  the  emotions,  and  in  a 
certain  sense  may  be  considered  muscles  of  expression.  Hence,  as  here- 
tofore shown,  if  a  person  would  read  or  speak  in  a  certain  way,  he  must 
excite  the  emotions  calculated  to  induce  the  desirable  action  of  the 
muscles.* 


*  That  the  action  of  these  muscles  are  in  part  involuntary  and  de- 
pendent on  the  state  of  the  nervous  system,  is  proved  by  the  groans  and 
cries  of  persons  operated  upon  by  the  surgeon  while  they  are  under  the 
influence  of  chloroform ;  and  by  the  cries  of  sick  persons,  particularly 
children,  such  that  the  disease,  can  by  a  skilful  person  be  detected  many 
times  by  the  moans  or  piercing  cries.  That  the  voice  may  have  expres- 
sion (so  also  the  manner),  it  will  be  well  for  the  student  not  to  devote  so 
much  time  to  imitating  gestures  (which  to  a  degree  is  well  enough),  as 
to  cultivating  a  power  of  calling  up  fervid  emotions  at  will.  And  n» 


SEC.  2.]  MODIFIERS  OF  SOUND.  385 

469.  The  state  of  the  general  health,  the  perfection  of  the  blood— de- 
pending in  its  turn  on  the  purity  of  the  air— the  proper  digestion  of  the 
food,  &c.,  &c.,  will  influence  the  condition  of  the  muscles. 

470.  But  if  the  muscles  be  healthy  and  exercised,  they 
must,  in  the  next  place,  be  properly  exercised. 

How  to  do  this  and  why  it  is  necessary,  is  easily  explained.  First, 
it  is  evident  that  words  are  made  up  of  simple  sounds,  as  in  case  of  the 
word  pen.  Here  is  an  aspirate  p,  a  tone  e,  and  a  subtone  n.  Now 
there  are  quite  a  number  of  muscles,  the  harmonious  action  of  which  is 
required  to  make  one  of  these  sounds— and  the  harmonious  action  of 
these  muscles  is  only  obtained  by  long  and  assiduous  practice.  Without 
this,  the  sound  is  apt  to  be  imperfectly  made,  will  of  course  be  indistinct, 
and  produce  quite  a  confusion  when  forming  part  of  a  word  or  sentence, 
perhaps  cause  the  sense  of  the  whole  to  be  misunderstood. 

471.  The  sounds  of  each  of  the  different  letters  of  pen,  are  spoken 
by  the  use  of  some  of  the  same  muscles,  and  by  the  use  of  some  different 
ones.  To  combine  the  action  of  the  muscles  required  when  the  word  is 
spoken  requires  very  much  exercise,  and  ought  not  certainly  to  be  at- 
tempted till  the  simple  sounds  have  been  mastered.  But  as  sp-eaking 
these  sounds  is  learned  in  early  years,  it  usually  falls  to  the  lot  of  a  stu- 
dent or  teacher  to  correct  evils  of  long  standing.  To  do  this,  the  sam« 
course  must  be  taken,  as  if  a  person  were  learning  for  the  first  time. 
They  must  be  trained  to  act  in  harmonious  perfection,  when  the  simple 
sounds  are  spoken,  and  then  trained  to  act  harmoniously  when  simple 
sounds  are  combined.  This  is  also  the  true  course  to  pursue,  wh^u 
learning  to  speak  a  foreign  language.  Thus  a  child,  when  learning  to 
read,  should  first  be  taught  to  pronounce  simple  sounds  perfectly — the 
sounds  of  the  letters,  not  the  names.  P,  as  usually  taught  to  a  child 
learning  its  alphabet,  is  a  compound  made  up  of  the  p  sound  and  th* 

none  but  actors  should  wish  to  have  the  power  of  calling  up  the  bad  pas- 
sions and  emotions  that  sometimes  live  in  the  human  breast,  the  student 
should  assiduously  cultivate  all  those  emotions  which  enniTble  man — 
which  render  him  kind  to  his  fellow-being  ;  and  his  patriotism,  nor 
selfish,  but  true  and  intense — then  will  his  living  emotions  control  his 
whole  action,  manner  and  bearing,  not  less  in  his  voice  than  otherwise  : 
and  that  moving  eloquence  which  is  from  the  heart,  will  make  an  abiding 
impression.  Thus  was  it  rather  than  by  "  holding  stones  in  his  mouth  " 
(though  these  minor  things  are  not  to  be  despised),  that  Demosthenf  <* 
governed  the  turbulent  spirits  of  Athens.  Thus  did  Cicero  compel  the 
Forum  to  resound  with  applause. 

17 


386  THE  VOICE.  [CHAP.  iv. 

sound  of  e — thus  pe.  These  simple  sounds,  are  usually  called  ele- 
mentary ;  and  according  to  Rush,*  are  thirty-five  in  number.  They 
should  be  thoroughly  learned  by  the  beginner,  whose  time  may  without 
harm  be  spent  upon  that  which  is  perfectly  mechanical.  Then  they 
should  be  combined  in  all  possible  ways ;  not  merely  such  as  are  found 
in  a  person's  native  language,  but  in  any  language  ;  for  thus  a  person 
will  not  only  speak  his  own  language  better,  but  will  have  that  control 
over  his  muscles  which  will  enable  him  to  speak- any  language  fluently 
in  a  very  short  time. 

472.  A  child  should  be  taught  to  read  by  note,  not  by  rote ;  for  as 
the  singer  who  is  well  exercised  in  every  combination  of  notes,  sings  any 
new  tune  very  readily — so  will  it  be  with  one  who  knows  perfectly  the 
elementary  sounds  of  speech,  and  their  almost  innumerable  combinations. 

473.  If  there  be   any  defect  of  speech,  such  as  stammering,  lisping, 
&c.,  not  owing  to  any  malformation  of  the  organs  of  speech,  it  can  be 
removed  by  training  the  organs  in  the  way  above  mentioned,  and,  in  ad- 
dition, throwing  out,  or  as  Rush  terms  it,  exploding   the   simple  and 
compound  sounds.     This  is  also  an  admirable  way  to  gain  strength  to 
the  voice,  when  feeble.t     To  do  this,  also  a  short  time  before  speaking, 
gives  flexibility  to  the  organs  of  speech. 

474.  To  speak  easily,  the  feet  must  be  kept  warm,  and  the  head  and 
throat  properly'  cool,  and  the  air  pure.1 


SECTION  3. — The  Larynx. 

475.  The  action  of  the  muscles  of  the  mouth  and  throat  are  so  evi- 
dent that  it  is  not  worth  while  to  dwell  upon  them,  as  it  is  upon  what  is 

*  T  3  the  works  of  this  distinguished  ornament  of  the  medical  profes- 
sion, the  curious  reader  is  with  satisfaction  referred  for  a  complete  con- 
sideration of  this  subject. 

t  It  is  evident,  that  feebleness  of  the  voice  is  not  all  dependent  on 
the  state  of  the  lungs,  except  they  are  very  much  diseased,  and  that  a 
person  may  use  the  voice  without  injuring  the  lungs ;  but  on  the  other 
h;md  it  may  have  the  effect  to  improve  them  and  the  whole  body,  for 
not ;0nly  when  speaking  does  a  person  inhale  more  air,  but  he  swallows 
a  tvditisiderabte  quantity  in  the  frothy  saliva. 

j  ?There,is  great 'danger  of  the  throat  becoming  too  hot  as  the  blood 
ojreufates  .very  actively  through  the  muscles  of  speech.  It  will  not  there- 
fore be"  prudent  to  dress  the  neck  warmly,  but  on  the  other  hand,  it 
should  be  sponged  outside,  and  gargled  within  with  cold  water. 


SEC.  3.] 


THE  LARYNX. 


387 


usually  considered  the  chief  organ  of  speech,  the  larynx.  Strange  to  say, 
the  action  of  this  part  is  not  well  understood.  A  view,  however,  of  its 
structure,  and  conjectured  uses,  will  not  be  uninteresting. 

476.  At  the  base  of  the  tongue,  a  bone  (Fig.  118)  is 
found,  called,  from  its  form,  the  hyoid  (U-shaped).  From 
it  a  ligament  and  other  connectives  pass  to  a  peculiar  shaped 
cartilage,  which  forms  the  top  of  the  windpipe,  and  the  chief 
part  of  the  larynx.  It  is  called  the  thyroid  (shield-shaped). 
Fig.  119  and  Fig.  120.  It  does  not  pass  round  the  back 
part  of  the  larynx.  A  sufficiently  clear  view  of  the  other 
three  cartilages,  is  obtained  from  Fig.  119,  and  its  explana- 
tion. 


Fig.  118. 


Fig.  119. 


Fig.  118.— it,  Hyoid  bone,  n,  Membrane  between  u  and  b,  thyroid  cartilage,  c,  CrJ- 
coid  cartilage. 

Fig.  119.— /,  Thyroid  cartilage,  front  view.  It  exists  in  the  front  part  of  the  upper 
portion  of  the  windpipe.  It  is  placed  downwards  from  its  position  in  the  cut  upon  c. 
The  sides  of  t ,  beins  outside  of  c,  which  is  called  the  cricoid  cartilage,  it  is  narrow  iu 
front  but  wide  behind  h,  h.  d.  The  bottom  of  the  ary  tenoid  cartilage  which  is  attached 
to  h. 

477.  A  view  of  the  internal  appearance  of  the  larynx,  is  obtained 
from  Fig.  121.  A  view  of  the  vocal  cords  and  their  relations,  is  better 
obtained  from  Fig.  122. 

By  most  it  is  thought,  and  it  would  seem  correctly,  that  the  tone* 


THE  VOICE. 


[CHAP.  IT. 


Fig.  120. 


Fig.  121. 


Fig.  120.— Side  view  of  larynx.  8,  Thyroid  cartilage.  9,  9,  Cricoid  cartilage,  12 
first  rings  of  trachea.  11,  Ligament  stretching  between  8  and  9.  JO,  Muscle,  the  con- 
traction of  which  draws  the  back  and  lower  part  of  8  towards  9,  thereby  relaxing  the 
vocal  cords. 

Fig.  121.— Section  of  face  or  one  side  of  the  division  of  the  nose.  1,  Nose.  2,  Vo- 
mer.  3,  Opening  into  the  nostril  behind  2.  4,  Roof  of  nose.  5,  Upper  jaw.  6,  Lower 
jaw.  7,  Tongue.  8,  Space  between  roof  of  the  mouth  and  the  tongue.  9,  Hyoid  bone. 
10,  Epiglottis.  11,  Arytenoid  cartilage.  12, 15,  Cricoid  cartilage.  13,  Membrane.  14, 
Thyroid  cartilage.  16,  Back  surface  of  throat  and  asophagus.  17,  Uvula  or  "  hanging 
point  in  the  mouth." 

Fig.  122.— View  from  above,  of  the  inside  of  the  larynx.  3,  3,  Vocal  cords.  1,  Space 
between  them,  through  which  the  air  passes  out.  8,  Thyroid  cartilage.  9,  9,  Cricoid 
cartilage.  2.  Arytenoid  cartilages.  7,  Muscle  which  by  contracting  would  tend  to 
make  the  vocal  cords  lax.  6,  Muscle  which  draws  2,  2.  toward  each  other.  4.  and  5, 
Muscles  adapted  to  move  the  arytenoid  cartilages,  and  thus  act  on  the  vocal  cords. 


SEC.  3.]  THE  LARYNX.  389 

of  the  voice,  are  produced  by  the  air  forced  through  the  opening  be- 
tween the  vocal  cords,  which  are  made  more  or  less  tense,  as  the  case 
may  require.  But  any  philosophy  yet  advanced  in  respect  to  the  par- 
ticular action  of  these  organs  has  objections. 


CHAPTER  V. 


ORGANS   OF  EXCRETION. 

478.  The  office  of  these  organs  is,  to  remove  from  the 
blood  all  substances  unfit  for  use  in  the  body. 

It  is  a  question,  whether  these  useless  substances  exist  in  the  blood, 
in  the  same  form  as  when  thrown  out  by  the  excreting  organs,  and  are 
therefore  merely  separated  from  the  blood,  or  are  formed  in  the  organs, 
in  which  case,  both  an  action  of  separating  and  decomposing  the  blood 
and  composing  the  substance,  would  take  place. 

It  is,  however,  found  that  there  are  several  of  these  organs  differently 
constituted,  removing  their  substances  in  different  ways,  and  also  remov- 
ing different  substances.  It  therefore  follows  that 

479.  There  are  different  kinds  of  waste  or  useless  sub- 
stances in  the  blood,  which  require  different  arrangements  for 
their  removal. 

Whether  the  necessary  difference  is  found  in  the  structure  of  the  dif- 
ferent organs,  or  in  the  structure  and  nervous  influence  exerted  upon 
them,  or  in  the  nervous  influence  only,  is  uncertain.  There  are  strong 
indications  that  the  nervous  influence  can  exert  a  powerful  effect  upon 
the  character  of  the  action  of  an  excretory  organ.  For  when  by  disease, 
any  one  is  prevented  from  fulfilling  its  duties,  some  one,  or  all  of  the 
others  will  accomplish  the  task  in  its  stead. 

480.  The  number  of  excreting  organs,  could  not,  in  the 
present   stage  of  knowledge,  be  ascertained  by  any  other 
means,  than  observation  and  experiment.     It  is  thus  learned 
there  are  five;  the  second  stomach,  liver,  lungs,  kidneys, 
and  skin.     The  divisions  of  this  chapter  are,  therefore,  evi- 
dent* 


SEC.  1.]  THE  SECOND  STOMACH,  COLON,  ETC.  891 

In  the  first  place,  however,  it  will  be  proper  to  make  some  remarks 
applicable  to  all. 

All  the  excreting  organs  have  other  duties  to  perform,  with  the  ex- 
ception of  the  kidneys,  which  seem  to  be  set  apart  for  the  especial  pur- 
pose of  excreting. 

481.  They  all  perform  their  duties  by  acting  on  the  blood,  which,  of 
course,  they  must  receive.      But  as  the  blood  contains,  at  different  times, 
different  proportions  of  the  material  the  different  organs  remove,  so  there 
must  be  a  means  of  increasing  the  circulation  through  each  organ,  as  the 
case  may  require,  viz.,  the  bloodvessels  of  these  organs  must  be  very 
susceptible  of  enlargement  and  diminution.     In  proof  of  which,  witness 
the  effect  produced  in  the  skin,  how  suddenly  it  is  flushed  or  paled. 

482.  To  increase  or  diminish,  and  to  sustain  and  direct  the  action  of 
these  organs,  they  must  receive  the  influence  of  the  nervous  system  of 
organic  life.     The  indirect  influence  of  the  mind  is  exhibited  so  evidently 
in  many  ways,  as  not  to  need  illustration. 

483.  It  is  also  very  worthy  of  notice,  that  the  blood  necessarily  con- 
tains a  certain  amount  of  useless  substance,  which  does  not,  however, 
cause  ill  health,  or  any  disturbance  in  the  system,  except  it  accumulate 
beyond  a  certain  amount.     On  the  other  hand,  its  existence  in  the  blood 
is  necessary  to  the  health  of  the  system,  as  nature  has  constituted  the 
excretory  organs  with  the  intent  that  they  should  have  something  to  do, 
and  they  suffer  without  the  intention  is  carried  out. 


SECTION  1. — The  Second  Stomach,  Colon,  fyc. 

484.  It  is  one  of  the  duties  of  these  organs  to  remove  con- 
tinually, a  large  amount  of  substance  from  the  blood,  which 
in  largo  quantities  visits  these  parts,  through  large  arterial 
branches  with  almost  infinite  subdivisions. 

485.  a.  The  first  thing  necessary  is,  that  the  substance  to  be  removed 
exist  in  the  blood.     This  is  produced  by  exercise.     Those,  therefore,  who 
are  sedentary,  are  liable  to  inactivity  of  these  organs,  which  exercise 
only  will  permanently  remove.     If  a  person  say  he  has  not  time  to  ex- 
ercise, let  him  remember  he  must  be  sick,  and  no  medicine  can  save  him. 

486.  6.  In  the  next  place,  if  the  substance  exist  in  the  blood,  it  must 
be  brought  to  the  organ.      This  is  favored  by  exercise  and  rubbing, 


392  ORGANS  OF  EXCRETION.  [cHAP.  V, 

which  quickens  the  circulation,  and  in  this  case,  kneading  the  abdomen, 
and  dashing  cold  water  upon  it ;  but  more  particularly  exercising  the 
muscles  of  the  abdomen  by  talking,  reading  aloud,  and  all  the  causes  of 
forcible  breathing,  are  of  great  benefit. 

487.  c.  In  the  next  place,  it  is  evident  that  if  the  brain  be  in  constant 
action  under  the  influence  of  a  mind  engrossed  by  business,  or  if  the 
mind  be  perplexed  or  melancholy,  the  duties  of  these  organs  will  b 
poorly  fulfilled.     It  is  useless  to  take  medicine  while  the  cause  of  derange 
ment  exists. 

488.  d.  Any  cause,  cold  feet,  fever,  &c.,  which  deranges  the  circula 
tion  of  the  blood,  will  prevent  the  healthy  action  of  the  organs  under  con 
sideration. 

489.  e.  As  the  excretion  is  removed  from  the  blood,  under  the  influ- 
ence of  the  organic  nervous  system,  all  causes  of  exhaustion,  either  of 
body  or  mind,  will  have  a  marked  influence  upon  these  organs. 

490.  /.  Every  part  of  the  body  is  influenced  much  by  habit,  and  these 
organs  as  much  as  any.     If  they  be  in  the  habit  of  daily  action,  it  is 
apt  to  be  regular,  but  if  a  regular  habit  of  these  organs  be  broken  up,  it 
will  be  very  difficult  to  preserve  the  pefect  health  of  any  part  long. 

491.  g.  This  daily  action  is  very  much  assisted  by  the  use  of  such  a 
portion  of  the  waste  food  that  these  organs  shall  be  reasonably  distended 
by  it,  and  stimulated  to  action. 

492.  A.  The  condition  of  the  weather  will  have  a  great  influence  upon 
these  organs.  In  warm  weather  the  system  does  not  feel  as  energetic  to 
exercise,  and  of  course  there  is  not  as  much  substance  furnished  as  in 
cold  weather.  In  warm  weather  the  skin  perspires  very  freely,  and  re- 
moves much  that  in  winter  will  be  removed  by  the  second  stomach,  kid- 
neys, and  lungs.  Hence,  in  summer  fruits  and  vegetables  must  be  eaten, 
that  the  waste  substance  they  contain  may  assist  in  preserving  the  daily, 
regular,  healthy  activity  of  these  parts.* 

493.  Not  only  should  these  organs  be  daily  active  in  removing  from 
the  blood  substance  which,  if  it  remained,  would  produce  headaches,  sal- 
low complexion,  derangement  of  the  digestive  organs,  but  it  is  a  golden 
rule,  that 

494.  There  should  be  some  regular  hour  when  the  colon 


*  It  is  worthy  of  note,  that  nature  has  furnished  to  man  plenty  of 
fruits  and  vegetables  in  warm  weather,  which  she  has  denied  him  in  cold 
weather. 


SEC.  2.]  THE  LIVER.  393 

should  be  called  on  to  remove  from  the  system  what  had  been 
removed  from  the  blood. 

The  hour  may  be  any  regular  one  of  the  greatest  convenience,  except 
in  case  of  people  subject  to  nervous  affections,  headaches,  disturbed  sleep, 
nightmare,  fits,  &c.,  when  the  hour  should  be  that  preceding  or  at  the 
time  of  retiring. 


SECTION  2. — The  Liver. 

495.  Some  suppose  the  bile  formed  in  the  liver  is  of  use  in  the  diges- 
tive process  only  ;  but  that  by  the  bile  the  system  is  relieved  of  substance 
harmful  if  it  remain,  and  that  the  quantity  of  bile  does  not  depend  upon 
the  digestive  process  entirely,  seems  to  admit  of  very  good  arguments. 

496.  The  liver  is  most  active  in  warm  weather. 

At  this  time  the  lungs  are  most  inactive  ;  the  second  stomach,  and 
colon  also,  in  health  not  active  ;  the  kidneys  inactive,  and  the  skin  active. 
Some  argue  that,  though  in  summer  there  is  less  food  required,  the  kind 
to  be  used,  requires  more  bile  to  digest  it.  But  one  or  two  other  facts 
seem  to  point  to  another  explanation. 

497.  The  bile  contains  much  carbon. 

This,  in  summer,  is  produced  in  the  system  by  its  wear  and  waste, 
but  must  not  be  removed  from  the  system  by  the  lungs,  or  heat  will  be 
produced.  It  is  not  required,  but  would  be  injurious.  In  hot  weather, 
therefore,  the  blood  passing  through  the  lungs  is  freed  from  its  carbon 
only  in  a  very  slight  degree  ;  for  the  lungs,  full  of  warm  air,  contain  com- 
paratively but  little  oxygen,  and  as  the  air  expands  but  little,  if  any,  but 
a  slight  effect  is  produced  ;  but  the  liver  being  very  active,  removes  car- 
bon in  plenty.  If  this  be  correct  reasoning,  it  accounts  for  the  fact,  that 

498.  The  lungs  and  liver  sympathize  with  each  other,  as 
the  expression  is. 

That  is,  if  one  fails  to  fulfil  its  duty,  the  other  will  be  forced  to  do  it ; 
on  which  account  the  circulation  must  be  increased,  and  this  continued 
for  a  short  time  produces  exhaustion  of  the  part,  inflammation,  or  some 
other  complaint. 

The  activity  of  the  liver  is  also  exhibited  by  the  fact,  that 


894  ORGANS  OF  EXCRETION.  [CHAP.  V. 

499.  In  summer,  exposure  of  the  skin  to  cold  tends  to 
produce  disease  of  the  liver. 

For  the  cold  acting  on  the  skin  contracts  it,  and  the  blood,  of  which 
its  vessels  are  full,  is  thrown  inward,  and  is  apt  to  congest  the  organs  of 
greatest  activity.  In  whiter,  this  affects  the  lungs  of  almost  all  persons, 
but  in  summer,  as  necessity  occasions  greater  activity  of  the  liver,  it  will 
be  overcharged  with  the  blood  which  in  winter  burdens  the  lungs,  and  a 
summer  complaint  instead  of  a  cold  results. 

500.  In  summer,  those  who  eat  large  quantities  of  food 
adapted  to  produce  heat  and  fatten  the  system,  are  very  sub- 
ject  to  affections  of  the  liver,  and  their  consequences — sum- 
mer complaints. 

For  if  the  food  be  digested,  it  must  be  removed  from  the  system,  or 
deposited  in  the  form  of  fat.  It  must  not  be  removed  by  its  natural  out- 
let, the  lungs,  but  by  the  liver ;  and  in  further  proof  of  this  it  will  be 
found,  that  those  who  grow  fat  are  not  troubled  with  affections  of  the 
liver  so  often  as  lean  people  who  eat  the  same  kind  of  food. 

501.  A  fact  in  regard  to  animals  tends  to  prove  the  same  thing. 
Geese  and  other  animals,  made  very  fat  by  a  process  of  stuffing,  have 
their  livers  enlarged  to  a  monstrous  size.  Swine  are  almost  invariably 
affected  with  disease  of  the  liver ;  while  animals  of  a  lean  character  na- 
turally, and  depending  much  on  the  lungs  for  heat,  are  almost  as  usually 
affected  with  disease  of  the  lungs.  Sheep,  for  instance,  after  shearing, 
are  greatly  troubled  with  inflammation  of  the  lungs.* 

502.  Persons  affected  with  disease  of  the  lungs,  which 
prevents  their  action  upon  the  air  in  a  sufficient  degree,  have 
disease  of  the  liver. 

As  in  consumptive  cases,  &c.  This  may  be  the  reason  of  the  condi- 
tion like  summer  complaint,  which  is  apt  to  be  exhibited  in  the  later 
periods  of  consumption. 

503.  Thus  causes  of  disease  of  the  liver,  and  the  conse- 
quent summer  complaints,  and  many  derangements  of  the  di- 
gestive organs,  may  be  considered  as  generally  resulting  from 

*  Of  more  than  two  hundred  lights  of  sheep  used  by  the  writer  in 
experimenting,  only  those  of  two  sheep  have  been  found  healthy ;  while 
of  an  equal  number  of  hogs'  lights,  very  few  were  affected. 


SEC.  3.]  THE  LUNGS.  395 

not  eating  sufficient  waste  food,  eating  too  much  fat  or  heat- 
producing  food,  exposure  to  cold,  and  incapacity  of  the  iungs 
to  perform  their  duty. 

The  above  causes  are  only  the  more  common  causes  of  disease  of 
the  liver,  &c.  As  the  formation  of  bile  is  dependent  on  the  reception 
of  blood  of  two  kinds,  the  arterial  blood  and  the  blood  from  the  portal 
vein  (Lith.  PI.  4,  Fig.  4),  and  on  nervous  influence  from  the  nervous 
system  of  organic  life  direct,  and  by  the  exertion  of  the  mind  indirectly ; 

504.  Causes  of  disease  of  the  liver  and  its  consequences 
may,  therefore,  also  be  looked  for  in  the  quality  and  quantity 
of  the  blood,  in  the  general  health  of  the  system,  and  par- 
ticularly of  the  digestive  organs ;  as  by  the  portal  veins  there 
is  a  very  intimate  relationship  established  between  all  the 
organs  of  this  group. 

The  liver  is  not,  therefore,  the  originator  of  all  the  diseases  that  are 
attributed  to  it ;  hence,  to  prevent  and  to  remove  its  diseases  or  their 
consequences,  attention  must  be  given  to  the  causes  of  disease  existing 
in  the  given  case. 

SECTION  3. — The  Lungs. 

* 

505.  These  organs  remove  carbon  and  water  from  the 
blood,  and  also  various  substances  in  very  small  quantities, 
depending  on  the  character  of  the  blood. 

If  it  contain  alcohol,  for  instance,  the  lungs  will  be  assiduous  in  re- 
moviflgit,  as  a  dangerous  enemy  of  the  system  ;  hence  the  breath  will  be 
odorous,  and  not  merely  because  a  portion  of  the  beverage  remains  in  the 
mouth  from  which  it  is  exhaled. 

The  chief  object  of  removing  the  carbon  has  been  shown  to  be  to 
produce  heat,  but  the  system  is  so  perfectly  organized,  that 

506.  If  the  carbon  be  not  eliminated  from  the  blood,  it 
tends  to  injure  the  action  of  every  part,  especially  the  ner- 
vous system. 

For  if  certain  kinds  of  air  be  breathed,  not  in  any  way  affecting  the 
lungs,  except  by  preventing  the  reception  of  oxygen — the  agent  causing 


396  ORGANS  OF  EXCRETION.          [CHAP.  V. 

the  purification  ol  the  blood  in  the  lungs — stupor  will  soon  be  produced. 
If  the  oxygen  be  in  small  quantities  only,  an  inactivity  of  the  system, 
want  of  vivacity  or  animation  in  the  eye  and  in  the  movements  will  be 
caused ;  a  want  of  life  will  be  exhibited  in  the  complexion ;  the  de- 
pression of  the  nervous  system  will  tend  to  cause  dyspepsia,  inactivity 
of  the  liver,  and  derangement  of  all  the  organs  of  the  second  process  of 
digestion ;  the  action  of  the  heart  will  be  enfeebled.  All  these  results, 
with  the  tendencies  mentioned  in  Sec.  2,  as  being  produced  by  the  non- 
removal  of  carbon  from  the  system,  together  with  the  effects  of  non- 
production  of  heat,  (from  want  of  oxygen  and  non-rer^oval  of  carbon  by 
which  heat  is  produced,)  are  most  unfavorable  to  health,  beauty,  and 
longevity.  It  therefore  follows  from  this  consideration  of  the  duties  of 
the  lungs,  that 

507.  Health,  mental  and  physical,  beauty,  elasticity  of 
body  or  mind,  strength  of  intellect,  or  development  of  the 
powers  of  the  system,  and  longevity,  are  unattainable  without 
the  inhalation  of  pure  air  in  proper  quantities. 

Hence,  all  who  desire  the  above  inestimable  blessings  must  leave  the 
system  uncompressed  by  clothing,  must  exercise  the  respiratory  organs 
in  all  proper  ways,  and  ventilate  their  apartments  night  and  day. 


SECTION  4. — The  Kidneys.     9 

508.  These  organs  are  two  in  number ;  one  upon  each 
side  of  the  back-bone  in  the  region  of  the  loins,  the  one  upon 
the  left  side  being  a  little  above  the  level  of  the  other. 

509.  They  are  permanent  in  their  position,  and  usually 
buried  in  a  large  quantity  of  fat. 

At  the  top  of  the  kidneys  is  a  small  part  called  the  renal  capsule  ;  its 
use  is  not  known. 

510.  The  color,  size,  internal  and  external  appearance 
of  the  kidney,  is  much  like  that  of  the  swine. 

511.  Its  use  is  twofold.      First,  to  remove  certain  solid 
substances ; 

Which,  however,  must  be  removed  by  being  dissolved  in  a  large  pro- 
portion of  water. 


SEC.  5.]  THE  SKIN.  397 

512.  Secondly,  it  is  the  duty  of  the  kidneys  to  remove 
fluid  from  the  blood,  when  the  bloodvessels  are  too  full. 

For  instance,  if  the  skin  be  exposed  to  cold,  and  is  contracted,  the 
blood  is  thrown  inward,  congesting  or  overcharging  some  of  the  internal 
organs — suppose  the  lungs  ;  the  chest  will  feel  "  stuffed,"  viz.,  full,  as  in 
reality  it  is,  and  sufficient  air  cannot  be  inhaled.  The  nervous  system 
instantly  exerts  itself  upon  the  kidneys,  enlarging  their  bloodvessels,  the 
watery  contents  of  which  are  at  once  diminished,  and  the  chest  feels 
relief:  it  therefore  follows,  that 

513.  The  kidneys  must  depend  for  their  action  upon  the 
reception  of  blood  and  nervous  influence. 

More  blood  passes  to  the  kidneys  than  to  any  other  parts  of  the  body 
of  the  same  size.  Its  arteries  are  very  large.  No  gland  or  part  in  the 
body  exhibits  the  regular  and  powerful  action  of  the  nervous  influence 
of  organic  life,  more  than  the  kidneys — while,  fortunately,  no  part  of  the 
body  is  less  influenced  by  any  state  of  the  mind.  For  the  action  of  the 
emotions  and  varying  states  of  the  mind  produce  such  an  effect  upon  the 
system  generally,  and  some  parts  in  particular,  that  the  uninfluenced 
action  of  the  kidney  is  required  to  prevent  too  great  disturbance  of  the 
circulation.  Another  striking  proof  of  the  perfection  reigning  in  the 
whole  system — and  with  thousands  of  others,  similar,  induce  the  most 
implicit  confidence  in  the  supervising  power  of  the  Ruler  of  the  universe 
and  the  Creator  of  man. 


SECTION  5.— The  Skin. 

514.  The  duties  of  this  organ  are  performed  so  quietly  that  its  impor- 
tance is  usually  overlooked,  or  very  much  undervalued.    It  has  been  de- 
monstrated by  many,  and  can  be  by  every  person  for  himself.     Sanc- 
torious,  an  Italian,  weighed  himself  and  all  he  ate  and  drank,  every  day 
for  thirty  years ;  the  result  of  his  experiments  prove  that  in  his  case,  about 
five-eighths  of  all  that  was  taken  into  the  system,  was  at  last  removed 
by  the  action  of  the  skin  and  lungs. 

515.  Seguin  and  Lavoisier  made  more  accurate  experiments  still ;  for 
by  inclosing  themselves  and  other  persons  in  glazed  bags  with  an  open- 
ing glued  about  the  mouth,  they  were  enabled  to  distinguish  between  the 
excretions  of  the  lungs  and  skin ;  and  they  came  to  the  conclusion,  that 


398  ORGANS  OF  EXCRETION.  [CHAP.  V. 

upon  an  average  two  pounds  pass  from  the  body  in  24  hours, by  the  action 
of  the  skin  in  health.  One  pound,  under  the  most  unfavorable  circum- 
stances, would  be  lost  by  the  action  of  the  skin,  and  five  pounds  in  a  single 
hour,  under  the  most  favorable  circumstances. 

516.  Some  persons  engaged  in  glass-blowing  were  weighed  by  the 
writer  some  years  since,  in  mid  winter.  One  man  weighed  170  pounds 
with  his  clothes  removed.  They  were  replaced,  and  his  labor  continued 
for  an  hour  and  three  quarters,  when  he,  with  others,  was  again  weighed ; 
his  weight  was  then  166  pounds,  he  had  lost  4  pounds'  weight  by  the  ac- 
tion of  the  skin  and  lungs  ;  the  person  who  lost  the  least,  lost  two  and  a  half 
pounds.  The  results  were  so  surprising  to  the  parties  they  would  hardly 
believe  them,  and  the  loss  is  so  gradual  and  imperceptible,  that  few  per- 
sons have  a  practical  belief  in  respect  to  the  action  of  the  skin  in  their 
own  case. 

517.  The  substance  passing  from  the  skin  may  be  con- 
sidered as  of  three  kinds  :  1st.  The  oil  previously  spoken  of, 
exuding  for  the  purpose  of  benefiting  the  skin  itself.    2d.  The 
perspiration,  properly  so  called  ;  it  is  the  water  portion  of  the 
blood,  perspired  that  by  evaporating  from  the  surface  it  may 
cool  the  body.    2d.  Excreted  substance  of  varying  character, 
as  the  case  may  be,  but  very  injurious  if  retained  in  the  sys- 
tem. 

518.  The  skin  therefore  in  health,  in  addition  to  the  duties 
mentioned  in  the  section  upon  the  nervous  system,  performs 
two  duties,  each   of  momentous  importance.     It   cools   the 
body,  more  or  less  rapidly,  and  thus  regulates  the  tempera- 
ture ;  in  the  next  place,  it  removes  waste  or  useless  substance 
from  the  body. 

519.  To  accomplish  these  duties,  the  skin  must  evidently 
be  liberally  supplied  with  blood. 

520.  This  is  accomplished — 

a.  By  exercise. 

For  exercise  drives  the  blood  through  every  part  of  the  body,  and  the 
muscles,  by  pressing  upon  the  bloodvessels  leading  to  and  from  the  skin, 
will  hurry  the  circulation  through  the  skin. 

b.  By  rubbing. 


SEC.  5.]  THE  SKIN.  399 

For  every  one,  from  experience,  knows  how  much  this  increases  the 
circulation  through  the  skin.  When  a  person  is  sick,  and  cannot  take 
exercise,  the  rubbing  becomes  doubly  necessary. 

c.  By  protective  clothing  and  shelter. 

Cold  necessarily  acts  on  the  bloodvessels  with  a  tendency  to  contract 
them,  and  there  is  such  liability  of  the  skin  to  exposure  to  the  cold,  its 
surface  is  so  extensive,  that  the  greatest  care  must  be  taken. 

d.  By  the  action  of  the  nervous  system  of  organic  life. 

This  is  the  power  which  resists  more  or  less  effectually  the  action 
of  the  cold.  Its  influence  upon  the  skin  is  very  powerful  in  healthy  per- 
sons. When  it  is  wanting,  the  bloodvessels  of  the  skin  become  bloodless, 
and  heat  alone  will  not  give  them  life  and  energy.  The  poor  sufferer 
with  the  fever  and  ague,  hopes  that  the  heat  of  the  fire  will  warm  his 
bloodless  skin  and  give  him  relief  from  his  dullness,  but  he  is  disappoint- 
ed ;  the  want  of  energy  manifested  by  the  nervous  system  will  prevent 
him  from  receiving  a  particle  of  benefit  from  the  warmth  ;  as  the  state 
of  the  nervous  system  depends  on  the  state  of  the  general  health. 

e.  By  whatever  tends  to  improve  the  general  health. 

Ill  health  of  any  organ,  by  acting  first  upon  the  nervous  system,  must 
nevertheless,  have  the  effect  to  derange  the  circulation  of  blood  in  the 
skin.  Thus  the  dyspeptic  is  apt  to  feel  a  coldness  of  the  skin,  and  any 
or  all  causes  of  ill  health  or  exhausted  states  of  the  system,  will  produce 
derangement  of  the  "  cutaneous"  (skin)  circulation,  and  all  the  conse- 
quences of  it. 

521.  The  substances  passing  from  the  skin,  make  their  exit  through 
exceedingly  small  holes  (Fig.  123),  which  are  likely  to  be  closed  by  any 
thing  adhering  to  the  surface  of  the  skin  ;  and  as  there  is  much  sub- 
stance passing  from  the  skin,  it  may  be  very  easily  glazed  over,  to  such 
a  degree  that  its  duties  cannot  be  performed. 

522.  It  is  necessary  to  avoid  all  causes  which  tend  to 
prevent  substances  separated  from  the  blood,  from  passing  out 
of  and  away  from  the  skin ;  for  which  purpose, 

a.  The  skin  must  be  often  and  thoroughly  cleansed. 

For  the  large  amount  of  substance  passing  from  the  skin  is  very  lia- 
ble, indeed  certain,  by  drying  to  form  a  gum  or  glazing  upon  the  sur- 
face of  the  skin,  which  closes  over  the  very  small  openings  through  which 
the  oil,  perspiration,  &c.,  are  removed,  preventing  their  discharge  and 


400 


OEGANS  OF  EXCRETION. 


[CHAP,  v 


causing  them  to  remain  in  the  system,  except  thrown  out  by  some  other 
organ.* 

Fig.  123. 


Fig.  123. — ocction  of  the  skin  magnified.  1,  The  cuticle,  the  proportionate  thickness 
of  which  varies.  2,  Rete  mucosum  (mucous  net- work)  so  called  because  it  is  of  pasty 
consistence  and  viewed  over  the  kiyers  beneath,  appears  in  the  form  of  a  net-work.  It 
varies  in  color  according  to  the  constitution  of  a  person,  its  frequent  deposition  from 
the  blood,  and  the  action  of  the  air  upon  it.  3,  Papillae,  in  which  the  nerves  commence. 
4,  Cutis-dermis  or  true  skin,  in  which  all  the  active  duties  of  the  skin  are  performed, 
and  which  in  health  depends  on  the  reception  of  blood  and  nervous  influence  by  the 
skin,  and  on  its  being  kept  clean.  5,  Cells  containing  fat.  6,  Perspiratory  gland,  with 
a  spiral  duct,  such  as  seen  in  the  hand  or  foot.  7,  Another  gland  with  straight  duct. 
8,  Two  hairs.  9,  A  pair  of  oil  glands  with  tubes  opening  into  the  hair  sheath 


*  The  question  is  frequently  asked,  Which  is  the  best  means  of  clean- 
ing the  skin  1  The  answer  is,  That  way  which  is  most  agreeable  to  a 
person,  if  the  system  be  perfectly  healthy  ;  if  it  be  not,  care  must  be  taken 
not  to  expose  the  skin  to  any  cause  of  chill,  to  which  a  person  will  be 
liable  in  proportion  to  the  feebleness  of  the  system,  produced  either  by 
disease  or  exhaustion.  When  cleaning  the  skin,  there  are  other  effects 
directly  produced,  which  render  it  advisable  to  take  a  view  of  the  differ- 
ent ways  at  present  adopted.  Some  merely  rub  the  skin  with  a  coarse 
towel,  hair-rubber,  or  the  like  ;  this  is  very  good,  and  sufficient  in  many 
cases,  if  done  very  thoroughly  and  as  often  as  twice  per  day.  If  this  be 
done  for  the  sick,  the  body  must  not  be  entirely  uncovered  at  once,  as 
the  nervous  system  will  not  be  able  to  resist  the  cold,  even  if  slight,  when 
acting  upon  so  much  surface  as  the  whole  body  presents.  How  much  of 


I'lG.  4.]  THE  SKIN.  401 

b.  The  clothing  surrounding  a  person,  either  that  which 
he  wears  or  covers  himself  with  during  sleep,  should  be  fre- 
quently cleansed. 

Oie  system  may  be  exposed,  will  depend  upon  the  health  of  the  person 
and  the  temperature  of  the  room.  The  best  thing,  not  to  say  it  is  the 
cheapest  or  most  convenient,  with  which  to  rub  sick  or  well  persons,  is  a 
pair  of  stocking-feet,  more  or  less  worn,  according  to  the  delicacy  of  the 
skin. 

Some  wash  the  skin  with  cold  water ;  this  is  well  if  reaction  be  im- 
mediately produced,  which  can  only  be  determined  by  experiment.  It 
must  not  be  tried  by  any  one,  however,  who  has  any  active  inflammation 
of  the  internal  organs,  for  when  cold  acts  on  the  skin,  it  always  drives 
the  blood  inward,  if  only  for  an  instant,  and  there  is  therefore  increased 
inflammation.  This  action,  however,  may  be  in  some  cases  followed  by 
"reaction,"  that  is,  such  an  enlargement  of  the  bloodvessels  of  the  skin, 
that  the  quantity  of  blood  in  the  inflamed  part  is  lessened.  It  is,  therefore, 
a  very  delicate  matter  to  apply  cold  to  a  feeble  person  so  as  not  to  be  inju- 
rious, and  there  is  such  a  latitude  of  effects  produced,  that  though  it  appears 
so  simple,  there  is  probably  no  remedy  or  thing  that  requires  more  skill  in 
its  application  than  cold  water.  If  it  be  applied,  and  reaction  does  not  take 
place,  brisk  rubbing,  and  if  the  person  can  bear  it,  active  exercise  should 
be  immediately  used.  The  extent  of  surface  which  may  be  washed  at 
once,  and  the  degree  of  cold,  must  depend  upon  the  health  and  warmth 
of  the  body,  and  upon  the  temperature  of  the  apartment.  It  is  always  to 
be  kept  in  mind,  that  all  applications  of  water  produce  a  cooling  of 
the  system  by  evaporation,  which  is  all  the  greater  on  account  of  the 
warmth  of  the  body. 

Some  dash,  pour,  or  shower  cold  water  upon  the  skin.  These 
things  tend  to  drive  the  blood  inward  and  to  produce  reaction  if  the 
system  be  sufficiently  vigorous.  The  effect  is  powerful,  as  the  running 
of  the  water  over  a  great  extent  of  surface,  removes  a  great  deal  of  heat, 
and  the  nervous  system  will  arouse  all  its  energies  to  rescue  the  body 
from  the  evil  to  which  it  is  exposed.  When,  therefore,  the  energies  of 
the  system  are  torpid,  such  applications  are  highly  beneficial ;  but  when 
the  system  is  in  reality  feeble,  the  greatest  harm  would  follow  from  such 
experiments,  which  must  not,  therefore,  be  tried  even  for  once,  by  those 
who  have  active  inflammation  or  tendency  to  it,  in  any  of  the  internal 
organs. 

Some  go  into  the  water,  or  apply  it  to  themselves  continuously.  In 
this  case  the  action  of  the  water  removes  a  great  deal  of  beat,  and  proves 
beneficial  when  the  system  is  not  feeble,  and  manifests  reaction  immedi- 
ately. It  should  not  be  continued  till  chill  is  felt,  as  the  powers  of  the 
system  can  only  produce  a  certain  amount  of  heat  with  profit.  Boys 
frequently  enfeeble  the  system  by  going  into  the  water  too  often.  There 
is  nothing  exhibits  more  strikingly  the  necessity  and  healthful  effect  of 
heat  upon  the  system.  The  body  is  not  made  stone  cold  by  b»*hing, 
but  a  lower  degree  of  temperature  than  is  natural  to  it  is  produced 
and  continued,  and  the  powers  of  the  system  are  more  completely  un- 


402  ORGANS  OF  EXCRETION.  [CHAP.  V. 

If  a  person  try  the  experiment  of  weighing  his  clothing  before  and 
after  it  is  washed,  he  will  find  its  weight  is  increased  by  wearing  it.  By 
trying  a  series  of  experiments,  he  will  find  his  clothing  is  more  soiled  if 

dermined  than  by  any  other  cause.  The  same  evil  is  more  gradually 
but  as  certainly  produced  by  young  ladies  who  dress  too  thinly,  by  which 
they  are  continually  in  a  bath  of  cold  air,  slow  but  sure  in  its  tendencies 
to  consumption,  and  every  other  complaint  which  is  consequent  upon  a 
depressed  state  of  the  temperature  of  the  body  for  any  length  of  time. 
The  degree  of  cold,  and  the  length  of  time  during  which  a  person  may 
take  this  kind  of  bath,  depends  upon  the  health. 

Some  prefer  warm  applications  in  place  of  cold.  They  are  better 
for  the  purpose  of  cleansing  the  skin,  but  they  do  not  excite  the  nervous 
system  to  action,  and  are  much  better  adapted  to  feeble  health  than  coll 
baths,  as  they  add  heat  rather  than  remove  it.  It  is  however  to  be  ob- 
served, that  they  evaporate  more  readily  than  cold  water,  and  a  person 
will  sometimes  feel  a  decided  chill  when  washing  before  a  hot  fire,  the 
evaporation  causing  so  much  heat  to  be  removed  from  the  system.  This 
is  especially  worthy  of  notice  when  a  person  is  unwell. 

Some  persons,  and  among  them  the  author,  prefer  the  vapor  bath,  as  it 
cleanses  the  skin  more  readily  than  any  other  simple  thing,  and  is  the  quick- 
est and  most  comfortably  taken  of  all  baths ;  while,  if  properly  taken,  a 
person  cannot  be  in  the  least  danger  of  taking  cold.  Like  all  warm 
baths,  they  should  not  be  applied  to  the  head  without  there  is  some  impe- 
rative necessity  for  it.  On  the  other  hand,  cold  should  be  applied  to  the 
head — the  principle  being  always  judicious,  "  to  keep  the  head  cool,  and 
extremities  warm."  In  the  second  place,  they  should  be  taken  only  till 
the  perspiration  begins  to  start.  This  will  be  first  perceived  on  the 
forehead,  though  it  be  not  exposed  to  the  vapor,  with  which  the  body  may 
be  very  wet.  If  there  be  but  little  blood  in  the  system,  the  enlargement 
of  the  vessels  by  the  warmth  applied  to  so  great  an  extent  of  surface  may 
cause  the  blood  to  be  drawn  from  the  feet ;  if  they  be  cold,  as  in  such  or 
any  case,  they  should  be  put  in  warm  water.  The  modes  of  taking  va- 
por baths  are  various.  Any  plan  of  producing  the  vapor  is  sufficient,  but 
the  more  rapidly  it  is  produced,  the  better.  One  of  the  most  important 
things  is,  to  have  the  covering  surrounding  a  person  thick,  as  this  prevents 
the  vapor  from  depositing  on  the  covering,  and  causes  it  to  deposit  on  the 
body.  An  extempore  bath  can  be  produced  by  placing  a  pail  of  water 
(if  hot  the  better)  under  a  chair  in  which  a  person  sits,  and  covering  him, 
except  the  head,  with  thick  "  comfortables,"  quilts,  blankets,  &c.  (one  thick- 
ness of  blanket  is  not  sufficient),  and  then  dropping  heated  stones,  burn- 
ing coals,  or  any  thing  hot,  into  the  water  in  the  pail.  As  soon  as  the 
perspiration  starts,  the  skin  should  be  rubbed  till  dry,  when  a  person  may 
retire  or  go  about  his  business.  If  he  be  well,  he  may,  if  he  choose, 
wash  the  skin  with  cold  water,  take  a  shower  or  plunge  bath,  as  do  the 
Russians ;  for  as  the  vapor  has  warmed  him,  he  will  not  be  injured  if  the 
cold  water  remove  heat.  There  is  no  danger  in  using  the  bath  at  any 
time,  except  just  after  eating  ;  it  soothes  the  nervous  system,  circulates 
the  blood  more  rapidly,  and  has  a  remarkable  tendency  to  calm  a  person 


SEC.  4.]  THE  SKIN.  403 

he  frequently  cleanse  the  skin,  and  also  if  the  clothing  be  frequently 
changed.  The  amount  of  substance  passing  from  the  system  can  be  de- 
monstrated to  affect  the  clothing  of  the  bed,  not  only  by  the  sense  of 
smell,  but  by  weighing  the  clothing  put  upon  the  bed  in  fall,  and  again 
in  spring.  In  sickness,  therefore,  a  person  should  have  his  linen  very  fre- 
quently changed,  and  several  times  per  day  he  should,  if  not  too  feeble, 
be  changed  from  one  bed  to  another,  that  the  clothing  of  the  one  he  has 
left  may  be  opened  and  aired.  No  PERSON  CAN  RECOVER  FROM  ILL  HEALTH 

SPEEDILY,  WITHOUT  EVERY  THING  BE  DONE  NECESSARY  TO  FACILITATE  THE 
ACTION  OF  THE  SKIN. 

c.  The  air  in  which  a  person  lives  should  be  kept  in  as 
proper  a  state  as  possible,  to  facilitate  the  passage  of  sub- 
stance from  the  skin. 

If  the  air  be  warm  and  dry,  evaporation  from  the  skin  takes  place 
rapidly,  while  if  it  be  moist  and  hot,  the  system  is  very  much  oppressed, 
as  every  one  has  experienced.  This  shows  the  importance  of  the  cuta- 
neous action.  If  the  weather  be  damp  and  cold  it  is  exceedingly  un- 
favorable, as  the  excretions  cannot  pass  from  the  system  through  the  skin, 
while  the  damp  air  by  its  nature  or  condition  removes  much  heat.  Hence 
cellars  and  like  places  are  the  most  unwholesome  of  abodes  ;  for  if  warm 
they  are  usually  damp  and  unwholesome,  if  they  be  cold  and  damp  as 
usual,  they  must  be  productive  of  very  much  disease. 


for  repose.  The  rubbing  that  should  follow  it,  and  the  application  of 
cold  to  any  part  requiring  its  influence,  is  most  excellent  when  a  per- 
son feels  stiff  and  weary,  rheumatic,  &c.  A  person  must  be  cartful  not 
to  use  it  for  too  long  a  time,  which  he  is  liable  to  do,  it  being  so 
soothing. 

Some  think  an  air  bath,  hot  or  cold,  exceedingly  serviceable.  The 
direction  of  Franklin  was  doubtless  discreet,  that  if  a  person  feels  rest- 
less and  sleepless,  he  should  rise,  throw  open  the  clothing,  and  walk  the 
chamber  for  a  few  moments. 

Some  have  great  confidence  in  what  are  called  medicated  baths  ;  but 
there  would  seem  to  be  very  little  effect  produced  by  these,  except  what 
is  caused  by  the  application  of  heat  or  moisture,  or  both  combined. 

Some  use  soap  in  connection  with  the  baths.  If  this  be  in  small 
quantities,  so  as  to  remove  only  the  oily  substance  from  the  surface  of 
the  skin,  it  is  not  injurious,  and  may  be  recommended  ;  but  used  plenti- 
fully, it  tends  to  draw  out  the  oil  from  the  skin. 

Some  use  alcoholics,  acids,  &c.,  upon  the  face  or  the  entire  skin. 
They  may  be  used,  but  very  unfrequently ;  frequently  used,  they  render 
the  skin  harsh,  dry,  and  liable  to  chap,  crack,  &c. 


404  ORGANS  OF  EXCRETION.  [CHAP.  V» 

523.  If  the  skin  from  any  cause  cannot  perform  its  duties, 
they  must  be  fulfilled  by  some  other  organ,  or  the  system  will 
quickly  suffer. 

If  the  perspiration  be  not  removed,  the  heat  of  the  system  will  accu- 
mulate and  a  feverish  state  soon  exist,  as  there  is  no  other  part  of  the 
body  which  can  fulfil  this  duty  of  the  skin.  In  such  case  the  heat  of 
the  system  can  be  lowered  only  by  drinking  water  and  sponging  the  sur- 
face with  cold  water,  which  by  evaporation  and  conduction  will  remove 
the  excessive  heat  of  the  body ;  and  as  it  is  always  harmful  to  have 
the  temperature  of  any  part  above  the  natural  degree,  it  should  be  kept 
down  by  the  above  means,  which  will  produce  a  chill  if  used  to  excess, 
and  thus  indicate  when  harm  is  commencing. 

If  the  excretion  be  not  removed,  it  is  usual  for  the  lining  of  the  nose 
to  first  undertake  all  it  can  do  ;  hence  why  a  person  has  a  "  cold  in  the 
head."  Next  the  continuation  of  the  same  lining  in  the  air  passages 
will  undertake  the  duty  unperformed  by  the  skin,  and  there  is  a  cold  in 
the  chest.  Sometimes  the  lining  of  the  second  stomach  undertakes  the 
task,  and  a  summer  complaint  is  the  result. 

524.  When   therefore    the   skin   from   inaction   causes 
increased  action  of  the  air  passages,  or  digestive  canal,  its 
action  must  be  increased. 

If  this  be  done  in  the  outset,  the  complaint  will  be  easily  removed, 
but  if  it  be  allowed  to  continue  a  short  time  the  "  cold  will  have  a  run." 

525.  Such  being  the  cause  of  colds,  it  is  easy  to  prevent 
them  by  clothing  the  skin  properly,  by  rubbing  the  skin,  and 
bathing  the  skin  in  such  a  manner  as  most  perfectly  to  pre- 
serve the  action  of  the  skin. 

526.  Also,  if  there  be  ^chronic  affections  of  the  air-passages 
and  digestive  canal,  it  will  be  highly  desirable  to  produce  and 
continue  a  very  active  condition  in  the  skin. 

527.  All  those  things  which  are  for  the  health  of  the  skin 
improve  also  its  beauty. 

Its  complexion  depends  upon  the  coloring  matter  deposited  from  the 
blood  and  acted  upon  by  the  air ;  there  must,  therefore,  be  an  active  cir- 
culation of  blood,  and  the  skin  must  be  kept  clean.  Exercise,  warm 


SEC.  4.]  THE  SKIN.  405 

clothing,  especially  of  the  hands  and  feet,  brisk  rubbing,  &c.,  improve 
beauty. 

528.  The  same  things  also  improve  the  appearance  of  the 
hair,  which  is  an  appendage  of  the  skin  (Fig.  123). 

It  grows  from  the  blood,  is  perfected  by  oil,  which  is  also  formed  from 
the  blood.  It  is  therefore  advisable  to  preserve  an  active  circulation  of 
blood  about  the  roots  of  the  hair,  and  when  it  is  falling  out,  to  attempt 
to  reproduce  it  by  brushing  the  places  where  it  is  desirable  to  have  it 
appear.* 

*  A  most  excellent  treatise  on  the  skin,  has  been  written  by  Eras- 
mus Wilson,  for  popular  reading.  In  it  directions,  with  the  reasons,  are 
given  for  treating  the  healthy  skin,  and  also  the  most  common  affections 
of  this  organ.  It  was  deemed  so  valuable  that  I  procured  its  republica- 
tion  in  a  cheap  form,  and  added  to  it  some  notes,  hoping  to  increase  its 
value.  It  is  illustrated  by  sixty-two  beautifully  engraved  figures  on  six 
steel  plates,  which  with  its  style  and  instructive  matter,  render  it  intense- 
ly interesting.  It  may  be  had  of  the  publishers  of  this  work,  in  paper 
covers,  37£  cents,  single  ;  $3  per  dozen. 


CHAPTER  VI. 


THE  OEGANIO   NERVOUS   SYSTEM. 

529.  This  is  also  called  the  sympathetic  nervous  system. 
The  source  of  the  influence  exerted  by  this  system  is  not 
known ;  there  are  probably  several  sources. 

530.  Upon  each  side  of  the  back-bone  and  a  little  dis- 
tance from  it  on  the  inside,  there  is  found  a  chain  of  nervous 
substance  (Fig.  124).     It  consists  of  small  lumps  of  grayish 
colored  nervous  substance  called  ganglia,  connected  by  mi- 
nute white  cords,  containing  also  gray  substance.     From  the 
ganglia,  connections  extend  to  the  neighboring  nerves  of  the 
spinal  system. 

531.  Nerves  from  this  chain  pass  off  on  the  large  blood- 
vessels, as  some  believe,  to  the  extremities  of  the  arteries,  but 
this  is  uncertain. 

532.  It  has  been  suggested  that  this  is  a  nervous  system  for  the  pur- 
pose of  harmonizing  the  action  of  all  parts  of  the  body,  but  of  this  there  is 
no  proof. 

533.  All  that  can  at  present  be  said,  is,  that  there  is  an 
arrangement  in  the  system  by  which  the  action  of  every  part 
produces  an  influence  on  every  other  part.  By  this  arrange- 
ment, the  action  of  every  part  in  health  is  increased  or  dimin- 
ished as  the  wants  of  every  part  and  the  whole  system  may 
require ;  of  which  there  have  been  given  so  many  illustrations 
in  the  preceding  pages,  it  is  hoped  that  the  reader  has  arrived 


Fig.  124 


408  THE  ORGANIC  NERVOUS  SYSTEM.  J>'HA?.  /» 

at  the  conclusion  that  the  physical  suffering  which  he  endure 
is  not  the  fault  of  the  organization  of  the  system,  but  of  him- 
self; in  not  learning  and  observing  those  wise  laws  established 
by  the  Creator  for  the  happiness  of  those  who  observe  them. 


Conclusion. 

When  all  the  principles  developed  by  studying  the  wants 
of  every  organ  are  reviewed,  the  laws  to  be  observed  for  the 
preservation  of  health,  &c.,  are  found  to  be  very  few,  and 
easily  regarded ;  to  wit,  all  the  organs  of  the  body  must  be 
properly  exercised,  that  is,  neither  too  much  nor  too  little ; 
regularly  and  lightly  at  first.  Food  is  to  be  chosen  in  ac- 
cordance with  the  temperature  of  the  weather,  exposure,  and 
exercise  of  the  system ;  prepared  without  much  spice  or 
seasoning ;  taken  neither  very  hot  nor  cold ;  thoroughly 
chewed  ;  and  in  such  quantity  as  to  merely  satisfy  a  healthy 
appetite.  Drink,  which  should  be  pure  water,  is  to  be  taken 
when  a  person  is  thirsty.  Pure  air  must  be  breathed.  The 
skin  kept  clean,  warm,  and  often  rubbed.  Regular  habits 
in  every  respect  should  be  formed,  and  a  cheerful,  amiable, 
and  active  state  of  mind  must  be  cultivated  and  preserved. 
If  sickness  do  come,  the  mental  and  physical  system  must  be 
allowed  rest  from  all  its  duties,  and  all  the  laws  of  health  must 
be  most  strictly  observed ;  as  the  first  rule  should  be,  not  to 
oppose  nature.  If  then,  she  need  assistance,  it  is  evident, 
that  those  best  qualified  by  honesty  of  feeling,  natural  talent, 
acquired  knowledge,  and  experience,  are  the  only  persons  in 
whom  confidence  can  be  placed. 


UNIVERSITY  OF  CALIFORNIA  L1BRA1 


